The Components of Loss on Derivative Instruments Net (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Derivative Instruments Gain Loss [Line Items]
Loss on derivative instruments, net	$ (102,785)	$ (41,615)
Interest Rate Swaps – Fair Value Adjustments
Derivative Instruments Gain Loss [Line Items]
Loss on derivative instruments, net	1,116	15,863
Interest Rate Swaptions
Derivative Instruments Gain Loss [Line Items]
Loss on derivative instruments, net	(3,027)
Interest Rate Swap
Derivative Instruments Gain Loss [Line Items]
Loss on derivative instruments, net	(21,423)	(29,412)
Futures Contracts
Derivative Instruments Gain Loss [Line Items]
Loss on derivative instruments, net	(94,016)	(17,382)
Futures Contracts – Losses From Maturities
Derivative Instruments Gain Loss [Line Items]
Loss on derivative instruments, net	(7,493)
Futures Contracts – Other Realized Losses
Derivative Instruments Gain Loss [Line Items]
Loss on derivative instruments, net	(22,374)	(18,606)
Mortgage Loan Purchase Commitments - Fair Value Adjustments
Derivative Instruments Gain Loss [Line Items]
Loss on derivative instruments, net	331
TBA Dollar Roll
Derivative Instruments Gain Loss [Line Items]
Loss on derivative instruments, net	23,155	20,821
TBA Dollar Rolls – Realized And Unrealized Gains (Losses)
Derivative Instruments Gain Loss [Line Items]
Loss on derivative instruments, net	$ 20,946	$ (12,899)