Quarterly report pursuant to Section 13 or 15(d)

Schedule of Repurchase Agreement Counterparties with Whom Repurchase Agreements Exceed 10 Percent of Stockholders' Equity (Details)

v3.3.0.814
Schedule of Repurchase Agreement Counterparties with Whom Repurchase Agreements Exceed 10 Percent of Stockholders' Equity (Details)
$ in Thousands
Sep. 30, 2015
USD ($)
Dec. 31, 2014
USD ($)
Repurchase Agreement Counterparty [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability $ 7,982,928 $ 12,932,463
Repurchase Agreement Counterparty, Royal Bank of Canada [Member]    
Repurchase Agreement Counterparty [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability 1,213,331 1,373,549
Repurchase Agreement Counterparty, Amount at Risk $ 325,870 $ 401,194
Repurchase Agreement Counterparty, Percent of Equity at Risk 9.00% 10.00%
Repurchase Agreement Counterparty, Weighted Average Days to Maturity 60.9 83.8
Repurchase Agreement Counterparty, Barclays Capital [Member]    
Repurchase Agreement Counterparty [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability $ 716,166 $ 1,346,085
Repurchase Agreement Counterparty, Amount at Risk $ 261,723 $ 365,879
Repurchase Agreement Counterparty, Percent of Equity at Risk 7.00% 9.00%
Repurchase Agreement Counterparty, Weighted Average Days to Maturity 43.0 50.5
Repurchase Agreement Counterparty, All Other Counterparties [Member]    
Repurchase Agreement Counterparty [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability $ 6,053,431 $ 9,215,329
Repurchase Agreement Counterparty, Amount at Risk $ 753,256 $ 907,066
Repurchase Agreement Counterparty, Percent of Equity at Risk 20.00% 22.00%
Repurchase Agreement Counterparty, Weighted Average Days to Maturity 57.6 57.7
Number of Repurchase Agreement Counterparties with Whom Repurchase Agreements Are Less Than 10 Percent of Stockholders' Equity 19 23
Repurchase Agreement Counterparty, Excluding Repurchase Agreements Collateralized by U.S. Treasuries [Member]    
Repurchase Agreement Counterparty [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability $ 7,982,928 $ 11,934,963
Repurchase Agreement Counterparty, Amount at Risk $ 1,340,849 1,674,139
US Treasury Securities [Member]    
Repurchase Agreement Counterparty [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability   1,996,250
Maturity on Demand [Member]    
Repurchase Agreement Counterparty [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability   997,500
Maturity on Demand [Member] | US Treasury Securities [Member]    
Repurchase Agreement Counterparty [Line Items]    
Assets Sold under Agreements to Repurchase, Repurchase Liability   $ 997,500