Annual report pursuant to Section 13 and 15(d)

Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance (Details)

v3.3.1.900
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative, Gain (Loss) on Derivative, Net $ (5,049) $ (17,529) $ 95,345
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments (210,621) (345,647) 245,229
Trading Gain (Loss) (217,338) (358,447) 320,559
Forward Contracts [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative, Gain (Loss) on Derivative, Net 0 (4,701) 38,297
Inverse Interest-Only Securities [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative, Gain (Loss) on Derivative, Net 36,066 55,028 (13,415)
Loan Purchase Commitments [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Gain (loss) on mortgage loans held-for-sale (1,668) 4,729 (20,015)
Interest Rate Risk Associated with the Investment Portfolio [Member] | Forward Contracts [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative, Gain (Loss) on Derivative, Net (39,748) (69,921) 151,021
Interest Rate Risk Associated with the Investment Portfolio [Member] | Short US Treasury Securities [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative, Gain (Loss) on Derivative, Net 125 (8) (991)
Interest Rate Risk Associated with the Investment Portfolio [Member] | Options Held [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative, Gain (Loss) on Derivative, Net 6,846 (14,070) 7,798
Interest Rate Risk Associated with the Investment Portfolio [Member] | Treasury Lock [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative, Gain (Loss) on Derivative, Net (837) 0 0
Interest Rate Risk Associated with the Investment Portfolio [Member] | Swap [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative, Gain (Loss) on Derivative, Net 6,164 6,340 (11,438)
Interest Rate Risk Associated with the Investment Portfolio [Member] | Interest Rate Swaption [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments (63,797) (242,795) 123,033
Interest Rate Risk Associated with the Investment Portfolio [Member] | Total Return Swap [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative, Gain (Loss) on Derivative, Net (13,371) 8,061 (1,087)
Interest Rate Risk Associated with the Investment Portfolio [Member] | Short [Member] | Interest Rate Swap [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments 52,785 201,536 (14,472)
Interest Rate Risk Associated with the Investment Portfolio [Member] | Long [Member] | Interest Rate Swap [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments (69,495) (114,121) 6,400
Interest Rate Risk Associated with Borrowings [Member] | Long [Member] | Interest Rate Swap [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments (130,114) (190,267) 130,268
Credit Risk Associated with Non-Agency RMBS and Residential Mortgage Loans Held-for-Sale [Member] | Credit Default Swap, Selling Protection [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative, Gain (Loss) on Derivative, Net $ (294) $ 1,742 $ (74,840)