CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified		Total	Preferred Stock, Cumulative Redeemable - Liquidation Preference $25.00 per Share: Series A Preferred Stock	Preferred Stock, Cumulative Redeemable - Liquidation Preference $25.00 per Share: Series B Preferred Stock	Common Stock, Par Value $.01:		Additional Paid-in Capital, in excess of Par:		Additional Paid-in Capital, in excess of Par: Series A Preferred Stock	Additional Paid-in Capital, in excess of Par: Series B Preferred Stock	Accumulated Deficit:	Accumulated Other Comprehensive Income/(Loss):
Balance at Dec. 31, 2011			$ 38	$ 0	$ 3,561		$ 2,795,925				$ (243,061)	$ (58,703)
Balance (in shares) at Dec. 31, 2011			3,840,000	0	356,112,000
Increase (Decrease) in Stockholders' Equity
Issuance of stock, net of expenses				0	30	[1]	15,432	[1]		0
Issuance of common stock, net of expenses (in shares)				0	2,966,000	[1]
Redemption of Series A Preferred Stock			0						0
Redemption of Series A Preferred Stock (in shares)			0
Shares issued for common stock option exercises							35
Equity-based compensation expense							6,488
Accrued dividends attributable to stock-based awards							0
Repurchase of shares of common stock	[1]				(16)		(12,156)
Repurchase of shares of common stock (in shares)	[1]				(1,532,000)
Net income		306,839									306,839
Dividends declared on common stock											(314,553)
Dividends declared on preferred stock		(8,160)									(8,160)
Dividends attributable to DERs											(1,373)
Issuance costs of redeemed Preferred Stock											0
Change in unrealized gains/(losses) on MBS and CRT securities, net		769,317										769,317
Change in unrealized (losses)/gains on derivative hedging instruments, net												51,363
Balance at Dec. 31, 2012		3,311,006	38	0	3,575		2,805,724				(260,308)	761,977
Balance (in shares) at Dec. 31, 2012			3,840,000	0	357,546,000
Increase (Decrease) in Stockholders' Equity
Issuance of stock, net of expenses				80	97	[1]	77,528	[1]		193,236
Issuance of common stock, net of expenses (in shares)				8,000,000	9,855,000	[1]
Redemption of Series A Preferred Stock			(38)						(92,015)
Redemption of Series A Preferred Stock (in shares)			(3,840,000)
Shares issued for common stock option exercises							0
Equity-based compensation expense							4,156
Accrued dividends attributable to stock-based awards							0
Repurchase of shares of common stock	[1]				(21)		(16,260)
Repurchase of shares of common stock (in shares)	[1]				(2,276,000)
Net income		302,709									302,709
Dividends declared on common stock											(594,318)
Dividends declared on preferred stock		(13,750)									(13,750)
Dividends attributable to DERs											(1,930)
Issuance costs of redeemed Preferred Stock											(3,947)
Change in unrealized gains/(losses) on MBS and CRT securities, net		(71,896)										(71,896)
Change in unrealized (losses)/gains on derivative hedging instruments, net												47,614
Balance at Dec. 31, 2013		3,142,251	0	80	3,651		2,972,369				(571,544)	737,695
Balance (in shares) at Dec. 31, 2013			0	8,000,000	365,125,000
Increase (Decrease) in Stockholders' Equity
Issuance of stock, net of expenses				0	50	[1]	35,590	[1]		0
Issuance of common stock, net of expenses (in shares)				0	5,305,000	[1]
Redemption of Series A Preferred Stock			0						0
Redemption of Series A Preferred Stock (in shares)			0
Shares issued for common stock option exercises							0
Equity-based compensation expense							8,581
Accrued dividends attributable to stock-based awards							(218)
Repurchase of shares of common stock	[1]				0		(2,688)
Repurchase of shares of common stock (in shares)	[1]				(346,000)
Net income		313,504									313,504
Dividends declared on common stock											(294,792)
Dividends declared on preferred stock		(15,000)									(15,000)
Dividends attributable to DERs											(764)
Issuance costs of redeemed Preferred Stock											0
Change in unrealized gains/(losses) on MBS and CRT securities, net		60,603										60,603
Change in unrealized (losses)/gains on derivative hedging instruments, net												(43,845)
Balance at Dec. 31, 2014		$ 3,203,272	$ 0	$ 80	$ 3,701		$ 3,013,634				$ (568,596)	$ 754,453
Balance (in shares) at Dec. 31, 2014			0	8,000,000	370,084,000

[1] For the year ended December 31, 2014, includes approximately $2.7 million (345,559 shares) surrendered for tax purposes related to equity-based compensation awards. For the year ended December 31, 2013, includes approximately $15.4 million (2,143,354 shares) repurchased through the Company’s publicly announced stock repurchase program and approximately $849,000 (132,276 shares) surrendered for tax purposes related to equity-based compensation awards. For the year ended December 31, 2012, includes approximately $9.7 million (1,240,291 shares) repurchased through the Company’s publicly announced stock repurchase program and approximately $2.5 million (291,803 shares) surrendered for tax purposes related to equity-based compensation awards.