Repurchase Agreements (Details 3) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Alpine Securitization Corporation/Credit Suisse
Repurchase agreements counterparty risk
Amount at Risk	$ 704,276	[1],[2]
Weighted Average Months to Maturity for Repurchase Agreements	1 month	[2]
Counterparty risk as percent of Stockholders' Equity, minimum	22.30%	[2]
Alpine Securitization Corporation
Repurchase agreements counterparty risk
Amount at Risk	677,200
Credit Suisse Securities USA LLC
Repurchase agreements counterparty risk
Amount at Risk	27,000
Wells Fargo
Repurchase agreements counterparty risk
Amount at Risk	357,260	[1],[3]
Weighted Average Months to Maturity for Repurchase Agreements	9 months	[3]
Counterparty risk as percent of Stockholders' Equity, minimum	11.30%	[3]
Wells Fargo Bank
Repurchase agreements counterparty risk
Amount at Risk	114,300
Wells Fargo Securities LLC
Repurchase agreements counterparty risk
Amount at Risk	242,900
UBS
Repurchase agreements counterparty risk
Amount at Risk	250,088	[1],[4],[5]
Weighted Average Months to Maturity for Repurchase Agreements	26 months	[4],[5]
Counterparty risk as percent of Stockholders' Equity, minimum	7.90%	[4],[5]
UBS AG
Repurchase agreements counterparty risk
Amount at Risk	239,900
UBS Securities LLC
Repurchase agreements counterparty risk
Amount at Risk	10,200
Deutsche Bank Securities, Inc.
Repurchase agreements counterparty risk
Amount at Risk	$ 206,555	[1]
Weighted Average Months to Maturity for Repurchase Agreements	2 months
Counterparty risk as percent of Stockholders' Equity, minimum	6.50%

[1] The amount at risk reflects the difference between (a) the amount loaned to the Company through repurchase agreements and repurchase agreements underlying Linked Transactions, including interest payable, and (b) the cash and the fair value of the securities pledged by the Company as collateral and MBS underlying Linked Transaction, including accrued interest receivable on such securities.

[2] Includes $677.2 million at risk with Alpine Securitization Corporation and $27.0 million at risk with Credit Suisse Securities (USA) LLC. Alpine Securitization Corporation is a special purpose funding vehicle that is a consolidated affiliate of Credit Suisse Group. Counterparty rating shown is the asset backed short term rating for Alpine Securitization Corporation.

[3] Includes $114.3 million at risk with Wells Fargo Bank, NA and $242.9 million at risk with Wells Fargo Securities LLC.

[4] Includes $239.9 million at risk with UBS AG and $10.2 million at risk with UBS Securities LLC.

[5] Includes Non-Agency MBS pledged as collateral with contemporaneous repurchase and reverse repurchase agreements.