Quarterly report pursuant to Section 13 or 15(d)

Notes Payable (Details)

v2.4.0.6
Notes Payable (Details) (USD $)
In Thousands, unless otherwise specified
6 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Debt Instrument [Line Items]    
Repayments of unsecured debt $ 50,000 $ 93,862
Debt instrument, interest rate, stated percentage 3.875%  
Unsecured Debt [Member] | 5.05% Unsecured Notes [Member]
   
Debt Instrument [Line Items]    
Repayments of unsecured debt $ 50,000  
Debt instrument, interest rate, stated percentage 5.05%