Annual report pursuant to Section 13 and 15(d)

Schedule III (Details)

v2.4.0.6
Schedule III (Details) (USD $)
12 Months Ended
Dec. 31, 2011
sqft
units
Dec. 31, 2010
sqft
Dec. 31, 2009
sqft
Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost, Land $ 514,396,000 [1]    
Initial Cost, Buildings and Improvements 1,470,262,000 [1]    
Net Improvements (Retirement) since Acquisition 465,214,000    
Gross Amounts at Which Carried at December 31, 2011, Land 509,409,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 1,940,463,000    
Gross Amounts at Which Carried at December 31, 2011, Total 2,449,872,000 [2]    
Accumulated Depreciation at December 31, 2011 535,732,000    
Net Rentable Square Feet 10,692,000 [3]    
Units 2,540    
Secured Debt 427,710,000 361,860,000  
Real Estate, Federal Income Tax Basis 2,148,544,000    
Property, Plant and Equipment, Useful Life, Minimum 3    
Property, Plant and Equipment, Useful Life, Maximum 50    
Square Footage of Real Estate Property 3,272,000,000 638,000,000 456,000,000
Land Available for Development 9,400,000    
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]      
Real estate assets, balance, beginning of period 2,443,127,000 2,341,461,000 2,326,646,000
Real estate assets, additions, property acquisitions 352,658,000 [4] 140,584,000 [4] 20,086,000 [4]
Real estate assets, improvements 36,386,000 [4] 28,196,000 [4] 30,399,000 [4]
Impairment - gross asset (16,416,000) 0 0
Real estate assets, deductions, write-off of disposed assets (1,648,000) (866,000) (2,451,000)
Real estate assets, deductions - property sales (364,235,000) (66,248,000) (33,219,000)
Real estate assets, balance, end of period 2,449,872,000 2,443,127,000 2,341,461,000
Real estate accumulated depreciation, balance, beginning of period 538,786,000 475,245,000 406,241,000
Real estate assets accumulated depreciation, additions - depreciation 84,167,000 83,302,000 82,022,000
Real estate assets accumulated depreciation, deductions, impairment write-down (1,291,000) 0 0
Real estate assets accumulated depreciation, deductions, write-off of disposed assets (1,648,000) (866,000) (2,451,000)
Real estate assets accumulated depreciation, deductions - property sales (84,282,000) (18,895,000) (10,567,000)
Real estate assets accumulated depreciation, balance, end of period 535,732,000 538,786,000 475,245,000
Multifamily Properties [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost, Land 70,956,000 [1]    
Initial Cost, Buildings and Improvements 85,559,000 [1]    
Net Improvements (Retirement) since Acquisition 196,244,000    
Gross Amounts at Which Carried at December 31, 2011, Land 74,268,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 278,491,000    
Gross Amounts at Which Carried at December 31, 2011, Total 352,759,000 [2]    
Accumulated Depreciation at December 31, 2011 107,508,000    
Net Rentable Square Feet 2,139,000 [3]    
3801 Connecticut [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Washington, DC [5]    
Initial Cost, Land 420,000 [1],[5]    
Initial Cost, Buildings and Improvements 2,678,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 7,999,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 420,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 10,677,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 11,097,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 8,145,000 [5]    
Year of Construction 1951 [5]    
Date of Acquisition Jan 1963 [5]    
Net Rentable Square Feet 179,000 [3],[5]    
Units 308 [5]    
Depreciation Life 30 [5],[6]    
Roosevelt Towers [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 336,000 [1]    
Initial Cost, Buildings and Improvements 1,996,000 [1]    
Net Improvements (Retirement) since Acquisition 8,932,000    
Gross Amounts at Which Carried at December 31, 2011, Land 336,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 10,928,000    
Gross Amounts at Which Carried at December 31, 2011, Total 11,264,000 [2]    
Accumulated Depreciation at December 31, 2011 6,759,000    
Year of Construction 1964    
Date of Acquisition May 1965    
Net Rentable Square Feet 170,000 [3]    
Units 191    
Depreciation Life 40 [6]    
Country Club Towers [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 299,000 [1]    
Initial Cost, Buildings and Improvements 2,562,000 [1]    
Net Improvements (Retirement) since Acquisition 13,532,000    
Gross Amounts at Which Carried at December 31, 2011, Land 299,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 16,094,000    
Gross Amounts at Which Carried at December 31, 2011, Total 16,393,000 [2]    
Accumulated Depreciation at December 31, 2011 8,763,000    
Year of Construction 1965    
Date of Acquisition Jul 1969    
Net Rentable Square Feet 159,000 [3]    
Units 227    
Depreciation Life 35 [6]    
Park Adams [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 287,000 [1]    
Initial Cost, Buildings and Improvements 1,654,000 [1]    
Net Improvements (Retirement) since Acquisition 8,568,000    
Gross Amounts at Which Carried at December 31, 2011, Land 287,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 10,222,000    
Gross Amounts at Which Carried at December 31, 2011, Total 10,509,000 [2]    
Accumulated Depreciation at December 31, 2011 6,902,000    
Year of Construction 1959    
Date of Acquisition Jan 1969    
Net Rentable Square Feet 173,000 [3]    
Units 200    
Depreciation Life 35 [6]    
Munson Hill Towers [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 322,000 [1]    
Initial Cost, Buildings and Improvements 3,337,000 [1]    
Net Improvements (Retirement) since Acquisition 14,496,000    
Gross Amounts at Which Carried at December 31, 2011, Land 322,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 17,833,000    
Gross Amounts at Which Carried at December 31, 2011, Total 18,155,000 [2]    
Accumulated Depreciation at December 31, 2011 11,855,000    
Year of Construction 1963    
Date of Acquisition Jan 1970    
Net Rentable Square Feet 258,000 [3]    
Units 279    
Depreciation Life 33 [6]    
The Ashby at McLean [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 4,356,000 [1]    
Initial Cost, Buildings and Improvements 17,102,000 [1]    
Net Improvements (Retirement) since Acquisition 13,414,000    
Gross Amounts at Which Carried at December 31, 2011, Land 4,356,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 30,516,000    
Gross Amounts at Which Carried at December 31, 2011, Total 34,872,000 [2]    
Accumulated Depreciation at December 31, 2011 16,628,000    
Year of Construction 1982    
Date of Acquisition Aug 1996    
Net Rentable Square Feet 274,000 [3]    
Units 256    
Depreciation Life 30 [6]    
Walker House Apartments [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland [5]    
Initial Cost, Land 2,851,000 [1],[5]    
Initial Cost, Buildings and Improvements 7,946,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 6,424,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 2,851,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 14,370,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 17,221,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 7,892,000 [5]    
Year of Construction 1971/03 [5]    
Date of Acquisition Mar 1996 [5]    
Net Rentable Square Feet 158,000 [3],[5]    
Units 212 [5]    
Depreciation Life 30 [5],[6]    
Bethesda Hill Apartments [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland [5]    
Initial Cost, Land 3,900,000 [1],[5]    
Initial Cost, Buildings and Improvements 13,412,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 11,726,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 3,900,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 25,138,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 29,038,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 12,413,000 [5]    
Year of Construction 1986 [5]    
Date of Acquisition Nov 1997 [5]    
Net Rentable Square Feet 226,000 [3],[5]    
Units 195 [5]    
Depreciation Life 30 [5],[6]    
Bennett Park [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 2,861,000 [1]    
Initial Cost, Buildings and Improvements 917,000 [1]    
Net Improvements (Retirement) since Acquisition 78,969,000    
Gross Amounts at Which Carried at December 31, 2011, Land 4,774,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 77,973,000    
Gross Amounts at Which Carried at December 31, 2011, Total 82,747,000 [2]    
Accumulated Depreciation at December 31, 2011 16,432,000    
Year of Construction 2007    
Date of Acquisition Feb 2001    
Net Rentable Square Feet 214,000 [3]    
Units 224    
Depreciation Life 28 [6]    
The Clayborne [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 269,000 [1]    
Initial Cost, Buildings and Improvements 0 [1]    
Net Improvements (Retirement) since Acquisition 30,376,000    
Gross Amounts at Which Carried at December 31, 2011, Land 699,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 29,946,000    
Gross Amounts at Which Carried at December 31, 2011, Total 30,645,000 [2]    
Accumulated Depreciation at December 31, 2011 7,288,000    
Year of Construction 2008    
Date of Acquisition Jun 2003    
Net Rentable Square Feet 60,000 [3]    
Units 74    
Depreciation Life 26 [6]    
The Kenmore [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Washington, DC [5]    
Initial Cost, Land 28,222,000 [1],[5]    
Initial Cost, Buildings and Improvements 33,955,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 839,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 28,222,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 34,794,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 63,016,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 4,431,000 [5]    
Year of Construction 1948 [5]    
Date of Acquisition Sep 2008 [5]    
Net Rentable Square Feet 268,000 [3],[5]    
Units 374 [5]    
Depreciation Life 30 [5],[6]    
Six Fifty North Glebe Road [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia [7]    
Initial Cost, Land 12,787,000 [1],[7]    
Initial Cost, Buildings and Improvements 0 [1],[7]    
Net Improvements (Retirement) since Acquisition 619,000 [7]    
Gross Amounts at Which Carried at December 31, 2011, Land 13,406,000 [7]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 0 [7]    
Gross Amounts at Which Carried at December 31, 2011, Total 13,406,000 [2],[7]    
Accumulated Depreciation at December 31, 2011 0 [7]    
Date of Acquisition Jun 2011 [7]    
Net Rentable Square Feet 0 [3],[7]    
Units 0 [7]    
1219 First Street [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia [7]    
Initial Cost, Land 14,046,000 [1],[7]    
Initial Cost, Buildings and Improvements 0 [1],[7]    
Net Improvements (Retirement) since Acquisition 350,000 [7]    
Gross Amounts at Which Carried at December 31, 2011, Land 14,396,000 [7]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 0 [7]    
Gross Amounts at Which Carried at December 31, 2011, Total 14,396,000 [2],[7]    
Accumulated Depreciation at December 31, 2011 0 [7]    
Date of Acquisition Nov 2011 [7]    
Net Rentable Square Feet 0 [3],[7]    
Units 0 [5],[7]    
Office Buildings [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost, Land 258,780,000 [1]    
Initial Cost, Buildings and Improvements 844,441,000 [1]    
Net Improvements (Retirement) since Acquisition 173,868,000    
Gross Amounts at Which Carried at December 31, 2011, Land 247,909,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 1,029,180,000    
Gross Amounts at Which Carried at December 31, 2011, Total 1,277,089,000    
Accumulated Depreciation at December 31, 2011 270,885,000    
Net Rentable Square Feet 4,793,000 [3]    
1901 Pennsylvania Avenue [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Washington, DC    
Initial Cost, Land 892,000 [1]    
Initial Cost, Buildings and Improvements 3,481,000 [1]    
Net Improvements (Retirement) since Acquisition 13,985,000    
Gross Amounts at Which Carried at December 31, 2011, Land 892,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 17,466,000    
Gross Amounts at Which Carried at December 31, 2011, Total 18,358,000 [2]    
Accumulated Depreciation at December 31, 2011 12,918,000    
Year of Construction 1960    
Date of Acquisition May 1977    
Net Rentable Square Feet 98,000    
Depreciation Life 28 [6]    
51 Monroe Street [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 840,000 [1]    
Initial Cost, Buildings and Improvements 10,869,000 [1]    
Net Improvements (Retirement) since Acquisition 22,095,000    
Gross Amounts at Which Carried at December 31, 2011, Land 840,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 32,964,000    
Gross Amounts at Which Carried at December 31, 2011, Total 33,804,000 [2]    
Accumulated Depreciation at December 31, 2011 23,326,000    
Year of Construction 1975    
Date of Acquisition Aug 1979    
Net Rentable Square Feet 218,000    
Depreciation Life 41 [6]    
515 King Street [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 4,102,000 [1]    
Initial Cost, Buildings and Improvements 3,931,000 [1]    
Net Improvements (Retirement) since Acquisition 5,116,000    
Gross Amounts at Which Carried at December 31, 2011, Land 4,102,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 9,047,000    
Gross Amounts at Which Carried at December 31, 2011, Total 13,149,000 [2]    
Accumulated Depreciation at December 31, 2011 4,323,000    
Year of Construction 1966    
Date of Acquisition Jul 1992    
Net Rentable Square Feet 73,000    
Depreciation Life 50 [6]    
6110 Executive Boulevard [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 4,621,000 [1]    
Initial Cost, Buildings and Improvements 11,926,000 [1]    
Net Improvements (Retirement) since Acquisition 10,447,000    
Gross Amounts at Which Carried at December 31, 2011, Land 4,621,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 22,373,000    
Gross Amounts at Which Carried at December 31, 2011, Total 26,994,000 [2]    
Accumulated Depreciation at December 31, 2011 14,418,000    
Year of Construction 1971    
Date of Acquisition Jan 1995    
Net Rentable Square Feet 199,000    
Depreciation Life 30 [6]    
1220 19th Street [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Washington, DC    
Initial Cost, Land 7,803,000 [1]    
Initial Cost, Buildings and Improvements 11,366,000 [1]    
Net Improvements (Retirement) since Acquisition 6,650,000    
Gross Amounts at Which Carried at December 31, 2011, Land 7,802,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 18,017,000    
Gross Amounts at Which Carried at December 31, 2011, Total 25,819,000 [2]    
Accumulated Depreciation at December 31, 2011 9,156,000    
Year of Construction 1976    
Date of Acquisition Nov 1995    
Net Rentable Square Feet 102,000    
Depreciation Life 30 [6]    
1600 Wilson Boulevard [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 6,661,000 [1]    
Initial Cost, Buildings and Improvements 16,742,000 [1]    
Net Improvements (Retirement) since Acquisition 13,632,000    
Gross Amounts at Which Carried at December 31, 2011, Land 6,661,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 30,374,000    
Gross Amounts at Which Carried at December 31, 2011, Total 37,035,000 [2]    
Accumulated Depreciation at December 31, 2011 13,647,000    
Year of Construction 1973    
Date of Acquisition Oct 1997    
Net Rentable Square Feet 168,000    
Depreciation Life 30 [6]    
7900 Westpark Drive [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 12,049,000 [1]    
Initial Cost, Buildings and Improvements 71,825,000 [1]    
Net Improvements (Retirement) since Acquisition 33,755,000    
Gross Amounts at Which Carried at December 31, 2011, Land 12,049,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 105,580,000    
Gross Amounts at Which Carried at December 31, 2011, Total 117,629,000 [2]    
Accumulated Depreciation at December 31, 2011 51,980,000    
Year of Construction 1972/'86/'99    
Date of Acquisition Nov 1997    
Net Rentable Square Feet 533,000    
Depreciation Life 30 [6]    
600 Jefferson Plaza [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 2,296,000 [1]    
Initial Cost, Buildings and Improvements 12,188,000 [1]    
Net Improvements (Retirement) since Acquisition 5,307,000    
Gross Amounts at Which Carried at December 31, 2011, Land 2,296,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 17,495,000    
Gross Amounts at Which Carried at December 31, 2011, Total 19,791,000 [2]    
Accumulated Depreciation at December 31, 2011 7,594,000    
Year of Construction 1985    
Date of Acquisition May 1999    
Net Rentable Square Feet 113,000    
Depreciation Life 30 [6]    
1700 Research Boulevard [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 1,847,000 [1]    
Initial Cost, Buildings and Improvements 11,105,000 [1]    
Net Improvements (Retirement) since Acquisition 3,378,000    
Gross Amounts at Which Carried at December 31, 2011, Land 1,847,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 14,483,000    
Gross Amounts at Which Carried at December 31, 2011, Total 16,330,000 [2]    
Accumulated Depreciation at December 31, 2011 7,129,000    
Year of Construction 1982    
Date of Acquisition May 1999    
Net Rentable Square Feet 101,000    
Depreciation Life 30 [6]    
Wayne Plaza [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 1,564,000 [1]    
Initial Cost, Buildings and Improvements 6,243,000 [1]    
Net Improvements (Retirement) since Acquisition 7,678,000    
Gross Amounts at Which Carried at December 31, 2011, Land 1,564,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 13,921,000    
Gross Amounts at Which Carried at December 31, 2011, Total 15,485,000 [2]    
Accumulated Depreciation at December 31, 2011 5,853,000    
Year of Construction 1970    
Date of Acquisition May 2000    
Net Rentable Square Feet 94,000    
Depreciation Life 30 [6]    
Courthouse Square [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 0 [1]    
Initial Cost, Buildings and Improvements 17,096,000 [1]    
Net Improvements (Retirement) since Acquisition 4,884,000    
Gross Amounts at Which Carried at December 31, 2011, Land 0    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 21,980,000    
Gross Amounts at Which Carried at December 31, 2011, Total 21,980,000 [2]    
Accumulated Depreciation at December 31, 2011 8,935,000    
Year of Construction 1979    
Date of Acquisition Oct 2000    
Net Rentable Square Feet 114,000    
Depreciation Life 30 [6]    
One Central Plaza [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 5,480,000 [1]    
Initial Cost, Buildings and Improvements 39,107,000 [1]    
Net Improvements (Retirement) since Acquisition 15,717,000    
Gross Amounts at Which Carried at December 31, 2011, Land 5,480,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 54,824,000    
Gross Amounts at Which Carried at December 31, 2011, Total 60,304,000 [2]    
Accumulated Depreciation at December 31, 2011 21,157,000    
Year of Construction 1974    
Date of Acquisition Apr 2001    
Net Rentable Square Feet 267,000    
Depreciation Life 30 [6]    
Atrium Building [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 3,182,000 [1]    
Initial Cost, Buildings and Improvements 11,281,000 [1]    
Net Improvements (Retirement) since Acquisition 2,844,000    
Gross Amounts at Which Carried at December 31, 2011, Land 3,182,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 14,125,000    
Gross Amounts at Which Carried at December 31, 2011, Total 17,307,000 [2]    
Accumulated Depreciation at December 31, 2011 5,626,000    
Year of Construction 1980    
Date of Acquisition July 2002    
Net Rentable Square Feet 80,000    
Depreciation Life 30 [6]    
1776 G Street [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Washington, DC    
Initial Cost, Land 31,500,000 [1]    
Initial Cost, Buildings and Improvements 54,327,000 [1]    
Net Improvements (Retirement) since Acquisition 4,193,000    
Gross Amounts at Which Carried at December 31, 2011, Land 31,500,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 58,520,000    
Gross Amounts at Which Carried at December 31, 2011, Total 90,020,000 [2]    
Accumulated Depreciation at December 31, 2011 18,549,000    
Year of Construction 1979    
Date of Acquisition Aug 2003    
Net Rentable Square Feet 262,000    
Depreciation Life 30 [6]    
Dulles Station II [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia [8]    
Initial Cost, Land 15,001,000 [1],[8]    
Initial Cost, Buildings and Improvements 494,000 [1],[8]    
Net Improvements (Retirement) since Acquisition (3,425,000) [8]    
Gross Amounts at Which Carried at December 31, 2011, Land 4,130,000 [8]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 7,940,000 [8]    
Gross Amounts at Which Carried at December 31, 2011, Total 12,070,000 [2],[8]    
Accumulated Depreciation at December 31, 2011 0 [8]    
Date of Acquisition Dec 2005 [8]    
Net Rentable Square Feet 0 [8]    
West Gude [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland [5]    
Initial Cost, Land 11,580,000 [1],[5]    
Initial Cost, Buildings and Improvements 43,240,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 5,817,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 11,580,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 49,057,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 60,637,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 10,659,000 [5]    
Year of Construction 1984/86/88 [5]    
Date of Acquisition Aug 2006 [5]    
Net Rentable Square Feet 275,000 [5]    
Depreciation Life 30 [5],[6]    
6565 Arlington Boulevard [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 5,584,000 [1]    
Initial Cost, Buildings and Improvements 23,195,000 [1]    
Net Improvements (Retirement) since Acquisition 4,120,000    
Gross Amounts at Which Carried at December 31, 2011, Land 5,584,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 27,315,000    
Gross Amounts at Which Carried at December 31, 2011, Total 32,899,000 [2]    
Accumulated Depreciation at December 31, 2011 6,215,000    
Year of Construction 1967    
Date of Acquisition Aug 2006    
Net Rentable Square Feet 130,000    
Depreciation Life 30 [6]    
Monument II [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 10,244,000 [1]    
Initial Cost, Buildings and Improvements 65,205,000 [1]    
Net Improvements (Retirement) since Acquisition 3,159,000    
Gross Amounts at Which Carried at December 31, 2011, Land 10,244,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 68,364,000    
Gross Amounts at Which Carried at December 31, 2011, Total 78,608,000 [2]    
Accumulated Depreciation at December 31, 2011 12,801,000    
Year of Construction 2000    
Date of Acquisition Mar 2007    
Net Rentable Square Feet 207,000    
Depreciation Life 30 [6]    
Woodholme Center [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 2,194,000 [1]    
Initial Cost, Buildings and Improvements 16,711,000 [1]    
Net Improvements (Retirement) since Acquisition 1,807,000    
Gross Amounts at Which Carried at December 31, 2011, Land 2,194,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 18,518,000    
Gross Amounts at Which Carried at December 31, 2011, Total 20,712,000 [2]    
Accumulated Depreciation at December 31, 2011 3,315,000    
Year of Construction 1989    
Date of Acquisition Jun 2007    
Net Rentable Square Feet 75,000    
Depreciation Life 30 [6]    
2000 M Street [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Washington, DC    
Initial Cost, Land 0 [1]    
Initial Cost, Buildings and Improvements 61,101,000 [1]    
Net Improvements (Retirement) since Acquisition 7,731,000    
Gross Amounts at Which Carried at December 31, 2011, Land 0    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 68,832,000    
Gross Amounts at Which Carried at December 31, 2011, Total 68,832,000 [2]    
Accumulated Depreciation at December 31, 2011 10,779,000    
Year of Construction 1971    
Date of Acquisition Dec 2007    
Net Rentable Square Feet 239,000    
Depreciation Life 30 [6]    
2445 M Street [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Washington, DC [5]    
Initial Cost, Land 46,887,000 [1],[5]    
Initial Cost, Buildings and Improvements 106,743,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 2,002,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 46,887,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 108,745,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 155,632,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 13,033,000 [5]    
Year of Construction 1986 [5]    
Date of Acquisition Dec 2008 [5]    
Net Rentable Square Feet 290,000 [5]    
Depreciation Life 30 [5],[6]    
Quantico Building E [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 4,518,000 [1]    
Initial Cost, Buildings and Improvements 24,801,000 [1]    
Net Improvements (Retirement) since Acquisition 63,000    
Gross Amounts at Which Carried at December 31, 2011, Land 4,518,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 24,864,000    
Gross Amounts at Which Carried at December 31, 2011, Total 29,382,000 [2]    
Accumulated Depreciation at December 31, 2011 2,234,000    
Year of Construction 2007    
Date of Acquisition June 2010    
Net Rentable Square Feet 134,000    
Depreciation Life 30 [6]    
Quantico Building G [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 4,897,000 [1]    
Initial Cost, Buildings and Improvements 25,376,000 [1]    
Net Improvements (Retirement) since Acquisition 48,000    
Gross Amounts at Which Carried at December 31, 2011, Land 4,897,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 25,424,000    
Gross Amounts at Which Carried at December 31, 2011, Total 30,321,000 [2]    
Accumulated Depreciation at December 31, 2011 2,373,000    
Year of Construction 2009    
Date of Acquisition June 2010    
Net Rentable Square Feet 136,000    
Depreciation Life 30 [6]    
1140 Connecticut Avenue [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Washington, DC    
Initial Cost, Land 25,226,000 [1]    
Initial Cost, Buildings and Improvements 50,495,000 [1]    
Net Improvements (Retirement) since Acquisition 2,327,000    
Gross Amounts at Which Carried at December 31, 2011, Land 25,226,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 52,822,000    
Gross Amounts at Which Carried at December 31, 2011, Total 78,048,000 [2]    
Accumulated Depreciation at December 31, 2011 2,188,000    
Year of Construction 1966    
Date of Acquisition Jan 2011    
Net Rentable Square Feet 185,000    
Depreciation Life 30 [6]    
1227 25th Street [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Washington, DC    
Initial Cost, Land 17,505,000 [1]    
Initial Cost, Buildings and Improvements 21,319,000 [1]    
Net Improvements (Retirement) since Acquisition 467,000    
Gross Amounts at Which Carried at December 31, 2011, Land 17,505,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 21,786,000    
Gross Amounts at Which Carried at December 31, 2011, Total 39,291,000 [2]    
Accumulated Depreciation at December 31, 2011 874,000    
Year of Construction 1988    
Date of Acquisition Mar 2011    
Net Rentable Square Feet 132,000    
Depreciation Life 30 [6]    
Braddock Place Member
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 18,817,000 [1]    
Initial Cost, Buildings and Improvements 71,250,000 [1]    
Net Improvements (Retirement) since Acquisition 112,000    
Gross Amounts at Which Carried at December 31, 2011, Land 18,818,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 71,361,000    
Gross Amounts at Which Carried at December 31, 2011, Total 90,179,000 [2]    
Accumulated Depreciation at December 31, 2011 1,157,000    
Year of Construction 1985    
Date of Acquisition Sep 2011    
Net Rentable Square Feet 345,000    
Depreciation Life 30 [6]    
John Marshall II Member
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia [5]    
Initial Cost, Land 13,490,000 [1],[5]    
Initial Cost, Buildings and Improvements 53,024,000 [1],[5]    
Net Improvements (Retirement) since Acquisition (41,000) [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 13,490,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 52,983,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 66,473,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 646,000 [5]    
Year of Construction 1996 [5]    
Date of Acquisition Sep 2011 [5]    
Net Rentable Square Feet 223,000 [5]    
Depreciation Life 30 [5],[6]    
Medical Office [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost, Land 62,902,000 [1]    
Initial Cost, Buildings and Improvements 313,897,000 [1]    
Net Improvements (Retirement) since Acquisition 33,752,000    
Gross Amounts at Which Carried at December 31, 2011, Land 64,896,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 345,655,000    
Gross Amounts at Which Carried at December 31, 2011, Total 410,551,000 [2]    
Accumulated Depreciation at December 31, 2011 83,363,000    
Net Rentable Square Feet 1,311,000 [3]    
Woodburn Medical Park I [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 2,563,000 [1]    
Initial Cost, Buildings and Improvements 12,460,000 [1]    
Net Improvements (Retirement) since Acquisition 4,198,000    
Gross Amounts at Which Carried at December 31, 2011, Land 2,563,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 16,658,000    
Gross Amounts at Which Carried at December 31, 2011, Total 19,221,000 [2]    
Accumulated Depreciation at December 31, 2011 7,339,000    
Year of Construction 1984    
Date of Acquisition Nov 1998    
Net Rentable Square Feet 73,000    
Depreciation Life 30 [6]    
Woodburn Medical Park II [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 2,632,000 [1]    
Initial Cost, Buildings and Improvements 17,574,000 [1]    
Net Improvements (Retirement) since Acquisition 3,960,000    
Gross Amounts at Which Carried at December 31, 2011, Land 2,632,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 21,534,000    
Gross Amounts at Which Carried at December 31, 2011, Total 24,166,000 [2]    
Accumulated Depreciation at December 31, 2011 9,290,000    
Year of Construction 1988    
Date of Acquisition Nov 1998    
Net Rentable Square Feet 96,000    
Depreciation Life 30 [6]    
8501 Arlington Boulevard [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia [5]    
Initial Cost, Land 2,071,000 [1],[5]    
Initial Cost, Buildings and Improvements 26,317,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 914,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 2,071,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 27,231,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 29,302,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 8,036,000 [5]    
Year of Construction 2000 [5]    
Date of Acquisition Oct 2003 [5]    
Net Rentable Square Feet 92,000 [5]    
Depreciation Life 30 [5],[6]    
8503 Arlington Boulevard [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia [5]    
Initial Cost, Land 1,598,000 [1],[5]    
Initial Cost, Buildings and Improvements 25,850,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 881,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 1,598,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 26,731,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 28,329,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 7,736,000 [5]    
Year of Construction 2001 [5]    
Date of Acquisition Oct 2003 [5]    
Net Rentable Square Feet 89,000 [5]    
Depreciation Life 30 [5],[6]    
8505 Arlington Boulevard [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia [5]    
Initial Cost, Land 2,819,000 [1],[5]    
Initial Cost, Buildings and Improvements 19,680,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 612,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 2,819,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 20,292,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 23,111,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 6,065,000 [5]    
Year of Construction 2002 [5]    
Date of Acquisition Oct 2003 [5]    
Net Rentable Square Feet 75,000 [5]    
Depreciation Life 30 [5],[6]    
Shady Grove Medical Village Ii Member
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 1,995,000 [1]    
Initial Cost, Buildings and Improvements 16,601,000 [1]    
Net Improvements (Retirement) since Acquisition 1,361,000    
Gross Amounts at Which Carried at December 31, 2011, Land 1,995,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 17,962,000    
Gross Amounts at Which Carried at December 31, 2011, Total 19,957,000 [2]    
Accumulated Depreciation at December 31, 2011 4,426,000    
Year of Construction 1999    
Date of Acquisition Aug 2004    
Net Rentable Square Feet 66,000    
Depreciation Life 30 [6]    
8301 Arlington Boulevard [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 1,251,000 [1]    
Initial Cost, Buildings and Improvements 6,589,000 [1]    
Net Improvements (Retirement) since Acquisition 1,460,000    
Gross Amounts at Which Carried at December 31, 2011, Land 1,251,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 8,049,000    
Gross Amounts at Which Carried at December 31, 2011, Total 9,300,000 [2]    
Accumulated Depreciation at December 31, 2011 2,259,000    
Year of Construction 1965    
Date of Acquisition Oct 2004    
Net Rentable Square Feet 49,000    
Depreciation Life 30 [6]    
Alexandria Professional Center [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 6,783,000 [1]    
Initial Cost, Buildings and Improvements 19,676,000 [1]    
Net Improvements (Retirement) since Acquisition 4,164,000    
Gross Amounts at Which Carried at December 31, 2011, Land 6,783,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 23,840,000    
Gross Amounts at Which Carried at December 31, 2011, Total 30,623,000 [2]    
Accumulated Depreciation at December 31, 2011 4,896,000    
Year of Construction 1968    
Date of Acquisition Apr 2006    
Net Rentable Square Feet 114,000    
Depreciation Life 30 [6]    
9707 Medical Center [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland [5]    
Initial Cost, Land 3,069,000 [1],[5]    
Initial Cost, Buildings and Improvements 11,777,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 863,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 3,069,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 12,640,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 15,709,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 2,812,000 [5]    
Year of Construction 1994 [5]    
Date of Acquisition Apr 2006 [5]    
Net Rentable Square Feet 38,000    
Depreciation Life 30 [5],[6]    
15001 Shady Grove Road [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 4,094,000 [1]    
Initial Cost, Buildings and Improvements 16,410,000 [1]    
Net Improvements (Retirement) since Acquisition 1,650,000    
Gross Amounts at Which Carried at December 31, 2011, Land 4,094,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 18,060,000    
Gross Amounts at Which Carried at December 31, 2011, Total 22,154,000 [2]    
Accumulated Depreciation at December 31, 2011 3,903,000    
Year of Construction 1999    
Date of Acquisition Apr 2006    
Net Rentable Square Feet 51,000    
Depreciation Life 30 [6]    
15005 Shady Grove [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland [5]    
Initial Cost, Land 4,186,000 [1],[5]    
Initial Cost, Buildings and Improvements 17,548,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 331,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 4,186,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 17,879,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 22,065,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 3,566,000 [5]    
Year of Construction 2002 [5]    
Date of Acquisition Jul 2006 [5]    
Net Rentable Square Feet 52,000 [5]    
Depreciation Life 30 [5],[6]    
Plumtree Medical Center [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland [5]    
Initial Cost, Land 1,723,000 [1],[5]    
Initial Cost, Buildings and Improvements 5,749,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 789,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 1,723,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 6,538,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 8,261,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 1,474,000 [5]    
Year of Construction 1991 [5]    
Date of Acquisition Jun 2006 [5]    
Net Rentable Square Feet 33,000 [5]    
Depreciation Life 30 [5],[6]    
2440 M Street [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Washington, DC    
Initial Cost, Land 12,500,000 [1]    
Initial Cost, Buildings and Improvements 37,321,000 [1]    
Net Improvements (Retirement) since Acquisition 4,514,000    
Gross Amounts at Which Carried at December 31, 2011, Land 12,500,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 41,835,000    
Gross Amounts at Which Carried at December 31, 2011, Total 54,335,000 [2]    
Accumulated Depreciation at December 31, 2011 8,080,000    
Year of Construction 1986/06    
Date of Acquisition Mar 2007    
Net Rentable Square Feet 112,000    
Depreciation Life 30 [6]    
Woodholme Medical Center [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland [5]    
Initial Cost, Land 3,744,000 [1],[5]    
Initial Cost, Buildings and Improvements 24,587,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 1,474,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 3,744,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 26,061,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 29,805,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 4,815,000 [5]    
Year of Construction 1996 [5]    
Date of Acquisition Jun 2007 [5]    
Net Rentable Square Feet 123,000 [5]    
Depreciation Life 30 [5],[6]    
Ashburn Farm Professional Cntr [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia [5]    
Initial Cost, Land 3,770,000 [1],[5]    
Initial Cost, Buildings and Improvements 19,200,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 1,006,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 3,770,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 20,206,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 23,976,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 3,570,000 [5]    
Year of Construction 1998/00/02 [5]    
Date of Acquisition Jun 2007 [5]    
Net Rentable Square Feet 75,000 [5]    
Depreciation Life 30 [5],[6]    
CentreMed I & II [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 2,062,000 [1]    
Initial Cost, Buildings and Improvements 12,506,000 [1]    
Net Improvements (Retirement) since Acquisition 489,000    
Gross Amounts at Which Carried at December 31, 2011, Land 2,062,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 12,995,000    
Gross Amounts at Which Carried at December 31, 2011, Total 15,057,000 [2]    
Accumulated Depreciation at December 31, 2011 2,201,000    
Year of Construction 1998    
Date of Acquisition Aug 2007    
Net Rentable Square Feet 52,000    
Depreciation Life 30 [6]    
4661 Kenmore Avenue [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia [8]    
Initial Cost, Land 3,764,000 [1],[8]    
Initial Cost, Buildings and Improvements 0 [1],[8]    
Net Improvements (Retirement) since Acquisition 1,994,000 [8]    
Gross Amounts at Which Carried at December 31, 2011, Land 5,758,000 [8]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 0 [8]    
Gross Amounts at Which Carried at December 31, 2011, Total 5,758,000 [2],[8]    
Accumulated Depreciation at December 31, 2011 0 [8]    
Date of Acquisition Aug 2007 [8]    
Net Rentable Square Feet 0 [8]    
Sterling Medical Office Bldg [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 970,000 [1]    
Initial Cost, Buildings and Improvements 5,274,000 [1]    
Net Improvements (Retirement) since Acquisition 887,000    
Gross Amounts at Which Carried at December 31, 2011, Land 970,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 6,161,000    
Gross Amounts at Which Carried at December 31, 2011, Total 7,131,000 [2]    
Accumulated Depreciation at December 31, 2011 1,128,000    
Year of Construction 1986    
Date of Acquisition May 2008    
Net Rentable Square Feet 36,000    
Depreciation Life 30 [6]    
Lansdowne Medical Office Building [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 1,308,000 [1]    
Initial Cost, Buildings and Improvements 18,778,000 [1]    
Net Improvements (Retirement) since Acquisition 2,205,000    
Gross Amounts at Which Carried at December 31, 2011, Land 1,308,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 20,983,000    
Gross Amounts at Which Carried at December 31, 2011, Total 22,291,000 [2]    
Accumulated Depreciation at December 31, 2011 1,767,000    
Year of Construction 2009    
Date of Acquisition Aug 2009    
Net Rentable Square Feet 85,000    
Depreciation Life 30 [6]    
Retail Centers [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Initial Cost, Land 121,758,000 [1]    
Initial Cost, Buildings and Improvements 226,365,000 [1]    
Net Improvements (Retirement) since Acquisition 61,350,000    
Gross Amounts at Which Carried at December 31, 2011, Land 122,336,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 287,137,000    
Gross Amounts at Which Carried at December 31, 2011, Total 409,473,000 [2]    
Accumulated Depreciation at December 31, 2011 73,976,000    
Net Rentable Square Feet 2,449,000 [3]    
Takoma Park [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 415,000 [1]    
Initial Cost, Buildings and Improvements 1,084,000 [1]    
Net Improvements (Retirement) since Acquisition 96,000    
Gross Amounts at Which Carried at December 31, 2011, Land 415,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 1,180,000    
Gross Amounts at Which Carried at December 31, 2011, Total 1,595,000 [2]    
Accumulated Depreciation at December 31, 2011 1,146,000    
Year of Construction 1962    
Date of Acquisition Jul 1963    
Net Rentable Square Feet 51,000    
Depreciation Life 50 [6]    
Westminster [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 519,000 [1]    
Initial Cost, Buildings and Improvements 1,775,000 [1]    
Net Improvements (Retirement) since Acquisition 9,041,000    
Gross Amounts at Which Carried at December 31, 2011, Land 519,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 10,816,000    
Gross Amounts at Which Carried at December 31, 2011, Total 11,335,000 [2]    
Accumulated Depreciation at December 31, 2011 5,801,000    
Year of Construction 1969    
Date of Acquisition Sep 1972    
Net Rentable Square Feet 150,000    
Depreciation Life 37 [6]    
Concord Centre [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 413,000 [1]    
Initial Cost, Buildings and Improvements 850,000 [1]    
Net Improvements (Retirement) since Acquisition 3,399,000    
Gross Amounts at Which Carried at December 31, 2011, Land 413,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 4,249,000    
Gross Amounts at Which Carried at December 31, 2011, Total 4,662,000 [2]    
Accumulated Depreciation at December 31, 2011 2,822,000    
Year of Construction 1960    
Date of Acquisition Dec 1973    
Net Rentable Square Feet 76,000    
Depreciation Life 33 [6]    
Wheaton Park [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 796,000 [1]    
Initial Cost, Buildings and Improvements 857,000 [1]    
Net Improvements (Retirement) since Acquisition 4,247,000    
Gross Amounts at Which Carried at December 31, 2011, Land 796,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 5,104,000    
Gross Amounts at Which Carried at December 31, 2011, Total 5,900,000 [2]    
Accumulated Depreciation at December 31, 2011 3,050,000    
Year of Construction 1967    
Date of Acquisition Sep 1977    
Net Rentable Square Feet 74,000    
Depreciation Life 50 [6]    
Bradlee [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 4,152,000 [1]    
Initial Cost, Buildings and Improvements 5,383,000 [1]    
Net Improvements (Retirement) since Acquisition 8,057,000    
Gross Amounts at Which Carried at December 31, 2011, Land 4,152,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 13,440,000    
Gross Amounts at Which Carried at December 31, 2011, Total 17,592,000 [2]    
Accumulated Depreciation at December 31, 2011 8,796,000    
Year of Construction 1955    
Date of Acquisition Dec 1984    
Net Rentable Square Feet 168,000    
Depreciation Life 40 [6]    
Chevy Chase Metro Plaza [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Washington, DC    
Initial Cost, Land 1,549,000 [1]    
Initial Cost, Buildings and Improvements 4,304,000 [1]    
Net Improvements (Retirement) since Acquisition 4,811,000    
Gross Amounts at Which Carried at December 31, 2011, Land 1,549,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 9,115,000    
Gross Amounts at Which Carried at December 31, 2011, Total 10,664,000 [2]    
Accumulated Depreciation at December 31, 2011 5,344,000    
Year of Construction 1975    
Date of Acquisition Sep 1985    
Net Rentable Square Feet 49,000    
Depreciation Life 50 [6]    
Montgomery Village Center [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 11,625,000 [1]    
Initial Cost, Buildings and Improvements 9,105,000 [1]    
Net Improvements (Retirement) since Acquisition 2,953,000    
Gross Amounts at Which Carried at December 31, 2011, Land 11,625,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 12,058,000    
Gross Amounts at Which Carried at December 31, 2011, Total 23,683,000 [2]    
Accumulated Depreciation at December 31, 2011 4,814,000    
Year of Construction 1969    
Date of Acquisition Dec 1992    
Net Rentable Square Feet 198,000    
Depreciation Life 50 [6]    
Shoppes of Foxchase [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 5,838,000 [1]    
Initial Cost, Buildings and Improvements 2,979,000 [1]    
Net Improvements (Retirement) since Acquisition 13,017,000    
Gross Amounts at Which Carried at December 31, 2011, Land 5,838,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 15,996,000    
Gross Amounts at Which Carried at December 31, 2011, Total 21,834,000 [2]    
Accumulated Depreciation at December 31, 2011 4,239,000    
Year of Construction 1960    
Date of Acquisition Jun 1994    
Net Rentable Square Feet 134,000    
Depreciation Life 50 [6]    
Frederick County Square [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 6,561,000 [1]    
Initial Cost, Buildings and Improvements 6,830,000 [1]    
Net Improvements (Retirement) since Acquisition 2,781,000    
Gross Amounts at Which Carried at December 31, 2011, Land 6,561,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 9,611,000    
Gross Amounts at Which Carried at December 31, 2011, Total 16,172,000 [2]    
Accumulated Depreciation at December 31, 2011 5,552,000    
Year of Construction 1973    
Date of Acquisition Aug 1995    
Net Rentable Square Feet 227,000    
Depreciation Life 30 [6]    
800 S. Washington Street [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Virginia    
Initial Cost, Land 2,904,000 [1]    
Initial Cost, Buildings and Improvements 5,489,000 [1]    
Net Improvements (Retirement) since Acquisition 5,965,000    
Gross Amounts at Which Carried at December 31, 2011, Land 2,904,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 11,454,000    
Gross Amounts at Which Carried at December 31, 2011, Total 14,358,000 [2]    
Accumulated Depreciation at December 31, 2011 3,255,000    
Year of Construction 1951/'55/'59/'90    
Date of Acquisition Jun 1998    
Net Rentable Square Feet 47,000    
Depreciation Life 30 [6]    
Centre at Hagerstown . [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 13,029,000 [1]    
Initial Cost, Buildings and Improvements 25,415,000 [1]    
Net Improvements (Retirement) since Acquisition 1,995,000    
Gross Amounts at Which Carried at December 31, 2011, Land 13,029,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 27,410,000    
Gross Amounts at Which Carried at December 31, 2011, Total 40,439,000 [2]    
Accumulated Depreciation at December 31, 2011 8,800,000    
Year of Construction 2000    
Date of Acquisition Jun 2002    
Net Rentable Square Feet 332,000    
Depreciation Life 30 [6]    
Frederick Crossing [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland [5]    
Initial Cost, Land 12,759,000 [1],[5]    
Initial Cost, Buildings and Improvements 35,477,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 1,675,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 12,759,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 37,152,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 49,911,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 8,959,000 [5]    
Year of Construction 1999-2003 [5]    
Date of Acquisition Mar 2005 [5]    
Net Rentable Square Feet 295,000 [5]    
Depreciation Life 30 [5],[6]    
Randolph Shopping Center [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 4,928,000 [1]    
Initial Cost, Buildings and Improvements 13,025,000 [1]    
Net Improvements (Retirement) since Acquisition 625,000    
Gross Amounts at Which Carried at December 31, 2011, Land 4,928,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 13,650,000    
Gross Amounts at Which Carried at December 31, 2011, Total 18,578,000 [2]    
Accumulated Depreciation at December 31, 2011 2,874,000    
Year of Construction 1972    
Date of Acquisition May 2006    
Net Rentable Square Feet 82,000    
Depreciation Life 30 [6]    
Montrose Shopping Center [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 11,612,000 [1]    
Initial Cost, Buildings and Improvements 22,410,000 [1]    
Net Improvements (Retirement) since Acquisition 2,220,000    
Gross Amounts at Which Carried at December 31, 2011, Land 11,612,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 24,630,000    
Gross Amounts at Which Carried at December 31, 2011, Total 36,242,000 [2]    
Accumulated Depreciation at December 31, 2011 5,080,000    
Year of Construction 1970    
Date of Acquisition May 2006    
Net Rentable Square Feet 145,000    
Depreciation Life 30 [6]    
Gateway Overlook [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland    
Initial Cost, Land 28,816,000 [1]    
Initial Cost, Buildings and Improvements 52,249,000 [1]    
Net Improvements (Retirement) since Acquisition 290,000    
Gross Amounts at Which Carried at December 31, 2011, Land 29,394,000    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 51,961,000    
Gross Amounts at Which Carried at December 31, 2011, Total 81,355,000 [2]    
Accumulated Depreciation at December 31, 2011 2,862,000    
Year of Construction 2007    
Date of Acquisition Dec 2010    
Net Rentable Square Feet 223,000    
Depreciation Life 30 [6]    
Olney Village Center Member
     
Real Estate and Accumulated Depreciation [Line Items]      
Location Maryland [5]    
Initial Cost, Land 15,842,000 [1],[5]    
Initial Cost, Buildings and Improvements 39,133,000 [1],[5]    
Net Improvements (Retirement) since Acquisition 178,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Land 15,842,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Buildings and Improvements 39,311,000 [5]    
Gross Amounts at Which Carried at December 31, 2011, Total 55,153,000 [2],[5]    
Accumulated Depreciation at December 31, 2011 582,000 [5]    
Year of Construction 1979 [5]    
Date of Acquisition Aug 2011 [5]    
Net Rentable Square Feet 198,000 [5]    
Depreciation Life 30 [5],[6]    
Prosperity Medical Center [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 42,997,000    
Kenmore Apartments [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 36,097,000 36,634,000  
Walker House Apartments [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 16,531,000    
West Gude [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 30,761,000 31,486,000  
Olney Village Center Member
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 23,873,000 0  
15005 Shady Grove [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 7,974,000 8,149,000  
Plumtree [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 4,419,000 4,512,000  
Bethesda Hill Apartments [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 29,099,000    
John Marshall II Member
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 53,936,000 0  
2445 M Street [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 95,593,000 [9] 94,339,000 [9]  
Ashburn Farm Professional Cntr [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 4,597,000    
Frederick Crossing [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 21,700,000 22,268,000  
9707 Medical Center [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 4,780,000 [10] 4,955,000 [10]  
3801 Connecticut [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 35,399,000 81,029,000 [11]  
Woodholme Medical Center [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Secured Debt 19,954,000 20,285,000  
650 North Glebe and 1219 First Street [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Land Available for Development 27,800,000    
Dulles Station II [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Land Available for Development 12,100,000    
Land Placed In Service $ 500,000    
4661 Kenmore Avenue [Member]
     
Real Estate and Accumulated Depreciation [Line Items]      
Land, Acres Held 0.8    
[1] The purchase cost of real estate investments has been divided between land and buildings and improvements on the basis of management’s determination of the fair values.
[2] At December 31, 2011, total land, buildings and improvements are carried at $2,148,544,000 for federal income tax purposes.
[3] Residential properties are presented in gross square feet.
[4] Includes non-cash accruals for capital items and assumed mortgages.
[5] At December 31, 2011, our properties were encumbered by non-recourse mortgage amounts as follows: $35,399,000 on 3801 Connecticut Avenue, $16,531,000 on Walker House, $29,099,000 on Bethesda Hill, $36,097,000 on The Kenmore, $30,761,000 on West Gude Drive,$95,593,000 on 2445 M Street, $53,936,000 on John Marshall II, $42,997,000 on Prosperity Medical Center, $4,780,000 on 9707 Medical Center Drive, $7,974,000 on 15005 Shady Grove Road, $4,419,000 on Plum Tree Medical Center, $19,954,000 on Woodholme Medical Center, $4,597,000 on Ashburn Farm, $21,700,000 on Frederick Crossing, and $23,873,000 on Olney Village Center.
[6] The useful life shown is for the main structure. Buildings and improvements are depreciated over various useful lives ranging from 3 to 50 years.
[7] As of December 31, 2011, WRIT had under development via joint venture arrangements, a mid-rise multifamily property in Arlington, Virginia (650 North Glebe) and a high-rise multifamily property in Alexandria, Virginia (1219 First Street). The total land value not yet placed into service of these development projects via joint venture arrangements at December 31, 2011 was $27.8 million.
[8] As of December 31, 2011, WRIT had land held for development in Herndon, VA (Dulles Station, Phase II). WRIT also held a 0.8 acre parcel of land at 4661 Kenmore for future medical office development. Additionally, WRIT had investments in various smaller development or redevelopment projects. The total land value not yet placed in service of these development projects at December 31, 2011 was $9.4 million. $0.5 million of Dulles Station, Phase II land was placed into service upon the completion of a portion of the parking garage structure.
[9] Interest only is payable monthly until the maturity date upon which all unpaid principal and interest are payable in full.
[10] The mortgage bears a set interest rate through June 30, 2012, at which time the rate will be reset based on the Moody's Long-term Corporate Bond Yield Average, but never lower than 5.0% per annum. The interest rate will be reset annually thereafter for the duration of the note. Principal and interest are payable monthly until July 1, 2028, at which time all unpaid principal and interest are payable in full. During the first 90 days of 2013, the lender has the option to elect to accelerate the maturity date of the note to July 1, 2013. For the remainder of 2013, we have the right to prepay the note without any prepayment penalties.
[11] Interest only is payable monthly until the maturity date, which can be extended for one year upon which the interest rate is reset on June 1, 2016. At maturity on June 1, 2017, all unpaid principal and interest are payable in full.