Fair Value of Financial Instruments (Details 2) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Financial Assets:
Agency MBS	$ 6,697,689		$ 7,225,460
Securities obtained and pledged as collateral	252,796		408,833
Restricted cash	59,275		5,016
Linked Transactions	23,940		12,704
Other derivative instruments	4,629		203
Financial Liabilities:
Repurchase agreements	8,568,171	[1]	8,752,472	[1]
Securitized debt	419,693	[2]	646,816	[2]
Obligation to return securities obtained as collateral	252,796		508,827
Senior Notes	100,000		100,000
Carrying Value
Financial Assets:
Agency MBS	6,697,689		7,225,460
Non-Agency MBS, including MBS transferred to consolidated VIEs	4,973,378		5,382,165
Securities obtained and pledged as collateral	252,796		408,833
Cash and cash equivalents	503,852		401,293
Restricted cash	59,275		5,016
Linked Transactions	23,940		12,704
Other derivative instruments	4,629		203
Financial Liabilities:
Repurchase agreements	8,568,171		8,752,472
Securitized debt	419,693		646,816
Obligation to return securities obtained as collateral	252,796		508,827
Senior Notes	100,000		100,000
Other derivative instruments	65,253		63,034
Estimated Fair Value
Financial Assets:
Agency MBS	6,697,689		7,225,460
Non-Agency MBS, including MBS transferred to consolidated VIEs	4,973,378		5,382,165
Securities obtained and pledged as collateral	252,796		408,833
Cash and cash equivalents	503,852		401,293
Restricted cash	59,275		5,016
Linked Transactions	23,940		12,704
Other derivative instruments	4,629		203
Financial Liabilities:
Repurchase agreements	8,568,038		8,754,521
Securitized debt	418,700		647,070
Obligation to return securities obtained as collateral	252,796		508,827
Senior Notes	101,560		103,040
Other derivative instruments	$ 65,253		$ 63,034

[1] The fair value of securities pledged against the Company’s repurchase agreements was $10.189 billion and $10.550 billion at September 30, 2013 and December 31, 2012, respectively.

[2] Securitized Debt represents third-party liabilities of consolidated VIEs and excludes liabilities of the VIEs acquired by the Company that eliminate in consolidation. The third-party beneficial interest holders in the VIEs have no recourse to the general credit of the Company. (See Notes 10 and 15 for further discussion.)