Annual report pursuant to Section 13 and 15(d)

Derivative Instruments and Hedging Activities Schedule of Inverse Interest-Only Securities Reconciliation (Details)

v3.3.1.900
Derivative Instruments and Hedging Activities Schedule of Inverse Interest-Only Securities Reconciliation (Details) - USD ($)
$ in Thousands
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Derivatives, Fair Value [Line Items]      
Interest Receivable $ 49,970 $ 65,529  
Derivative, Notional Amount 21,998,381 48,115,523 $ 37,366,610
Inverse Interest-Only Securities [Member]      
Derivatives, Fair Value [Line Items]      
Interest Receivable 1,676 2,188  
Derivative, Notional Amount 932,037 1,168,226 $ 1,525,845
Derivative, Unamortized Premium 0 0  
Derivative, Designated Credit Reserve 0 0  
Derivative, Net, Unamortized (792,178) (991,715)  
Derivative, Amortized Cost Basis 139,859 176,511  
Derivative, Gross Unrealized Gains 19,655 14,162  
Derivative, Gross Unrealized Losses (1,608) (4,269)  
Derivative, Carrying Value $ 157,906 $ 186,404