Collateral Positions (Details 2) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Collateral Positions
Total Fair Value of Assets Pledged and Accrued Interest		$ 11,433,938
Agency MBS
Collateral Positions
Total Fair Value of Assets Pledged and Accrued Interest	[1]	4,542,767
Legacy Non-Agency MBS
Collateral Positions
Total Fair Value of Assets Pledged and Accrued Interest	[2],[3]	2,829,209
RPL/NPL MBS
Collateral Positions
Total Fair Value of Assets Pledged and Accrued Interest		2,627,458
U.S. Treasury securities
Collateral Positions
Total Fair Value of Assets Pledged and Accrued Interest		507,443
CRT securities
Collateral Positions
Total Fair Value of Assets Pledged and Accrued Interest		170,435
Residential whole loans
Collateral Positions
Total Fair Value of Assets Pledged and Accrued Interest		685,088
Cash
Collateral Positions
Total Fair Value of Assets Pledged and Accrued Interest	[4]	71,538
Securities Sold under Agreements to Repurchase and Other Advances
Collateral Positions
Fair Value		11,301,255
Amortized Cost		10,744,311
Accrued Interest on Pledged Assets		23,461
Securities Sold under Agreements to Repurchase and Other Advances | Agency MBS
Collateral Positions
Fair Value	[1]	4,493,525
Amortized Cost	[1]	4,465,081
Accrued Interest on Pledged Assets	[1]	10,593
Securities Sold under Agreements to Repurchase and Other Advances | Legacy Non-Agency MBS
Collateral Positions
Fair Value	[2],[3]	2,818,968
Amortized Cost	[2],[3]	2,278,870
Accrued Interest on Pledged Assets	[2],[3]	10,241
Non-Agency MBS acquired from consolidated VIEs in connection with resecuritization transactions		570,500
Non-Agency MBS pledged as collateral in connection with contemporaneous repurchase and reverse repurchase agreements entered into with a single counterparty		726,700
Securities Sold under Agreements to Repurchase and Other Advances | RPL/NPL MBS
Collateral Positions
Fair Value		2,625,866
Amortized Cost		2,644,797
Accrued Interest on Pledged Assets		1,592
Securities Sold under Agreements to Repurchase and Other Advances | U.S. Treasury securities
Collateral Positions
Fair Value		507,443
Amortized Cost		507,443
Accrued Interest on Pledged Assets		0
Securities Sold under Agreements to Repurchase and Other Advances | CRT securities
Collateral Positions
Fair Value		170,352
Amortized Cost		173,367
Accrued Interest on Pledged Assets		83
Securities Sold under Agreements to Repurchase and Other Advances | Residential whole loans
Collateral Positions
Fair Value		684,136
Amortized Cost		673,788
Accrued Interest on Pledged Assets		952
Securities Sold under Agreements to Repurchase and Other Advances | Cash
Collateral Positions
Fair Value	[4]	965
Amortized Cost	[4]	965
Accrued Interest on Pledged Assets	[4]	0
Derivative Hedging Instruments
Collateral Positions
Fair Value		109,142
Amortized Cost		110,033
Accrued Interest on Pledged Assets		80
Derivative Hedging Instruments | Agency MBS
Collateral Positions
Fair Value	[1]	38,569
Amortized Cost	[1]	39,460
Accrued Interest on Pledged Assets	[1]	80
Derivative Hedging Instruments | Legacy Non-Agency MBS
Collateral Positions
Fair Value	[2],[3]	0
Amortized Cost	[2],[3]	0
Accrued Interest on Pledged Assets	[2],[3]	0
Derivative Hedging Instruments | RPL/NPL MBS
Collateral Positions
Fair Value		0
Amortized Cost		0
Accrued Interest on Pledged Assets		0
Derivative Hedging Instruments | U.S. Treasury securities
Collateral Positions
Fair Value		0
Amortized Cost		0
Accrued Interest on Pledged Assets		0
Derivative Hedging Instruments | CRT securities
Collateral Positions
Fair Value		0
Amortized Cost		0
Accrued Interest on Pledged Assets		0
Derivative Hedging Instruments | Residential whole loans
Collateral Positions
Fair Value		0
Amortized Cost		0
Accrued Interest on Pledged Assets		0
Derivative Hedging Instruments | Cash
Collateral Positions
Fair Value	[4]	70,573
Amortized Cost	[4]	70,573
Accrued Interest on Pledged Assets	[4]	0
Repurchase Agreements | Non-Agency MBS
Collateral Positions
Non-Agency MBS acquired from consolidated VIEs in connection with resecuritization transactions		570,500	$ 1,275,000
Non-Agency MBS pledged as collateral in connection with contemporaneous repurchase and reverse repurchase agreements entered into with a single counterparty		726,700	$ 731,000
Federal Home Loan Bank Advances | Securities Sold under Agreements to Repurchase and Other Advances | Agency MBS
Collateral Positions
Fair Value		1,612,000
Amortized Cost		1,606,000
Accrued Interest on Pledged Assets		$ 3,900

[1] Includes Agency MBS pledged under FHLB advances with an aggregate fair value of $1.612 billion, aggregate amortized cost of $1.606 billion and aggregate accrued interest of approximately $3.9 million at December 31, 2015.

[2] In addition, at December 31, 2015, $726.7 million of Legacy Non-Agency MBS are pledged as collateral in connection with contemporaneous repurchase and reverse repurchase agreements entered into with a single counterparty.

[3] Includes $570.5 million of Legacy Non-Agency MBS acquired in connection with resecuritization transactions from consolidated VIEs at December 31, 2015, that are eliminated from the Company’s consolidated balance sheets.

[4] Cash pledged as collateral is reported as “Restricted cash” on the Company’s consolidated balance sheets.