Quarterly report pursuant to Section 13 or 15(d)

Unsecured Lines of Credit Payable - Schedule of Credit Unused and Available (Details)

v3.2.0.727
Unsecured Lines of Credit Payable - Schedule of Credit Unused and Available (Details) - USD ($)
Jun. 30, 2015
Jun. 23, 2015
Dec. 31, 2014
Line of Credit Facility [Line Items]      
Borrowings outstanding $ (185,000,000)   $ (50,000,000)
New Credit Facility      
Line of Credit Facility [Line Items]      
Committed capacity   $ 1,000,000,000.0  
Line of Credit | New Credit Facility      
Line of Credit Facility [Line Items]      
Committed capacity 600,000,000 $ 600,000,000  
Borrowings outstanding (185,000,000)    
Letters of credit issued (1) (15,474,000)    
Unused and available $ 399,526,000