CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Preferred Stock [Member]	Common Stock [Member]	Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income [Member]	Total
Beginning Balance at Dec. 31, 2010	$ 179,323	$ 703	$ 1,028,382	$ (354,883)	$ 173,900	$ 1,027,425
Net income	0	0	0	160,204	0	160,204
Change in unrealized gain on mortgage securities, net	0	0	0	0	54,325	54,325
Amounts related to cash flow hedges, net	0	0	0	0	(23,685)	(23,685)
Cash dividends:
Common	0	0	(5,407)	(139,835)	0	(145,242)
Preferred	0	0	0	(20,369)	0	(20,369)
Redemption of Series A and B preferred stock						0
Conversion of preferred stock	(15)	0	15	0	0	0
Additions to capital	5,206	180	234,663	0	0	240,049
Ending Balance at Dec. 31, 2011	184,514	883	1,257,653	(354,883)	204,540	1,292,707
Net income	0	0	0	163,626	0	163,626
Change in unrealized gain on mortgage securities, net	0	0	0	0	91,750	91,750
Amounts related to cash flow hedges, net	0	0	0	0	(2,380)	(2,380)
Cash dividends:
Common	0	0	(1,785)	(141,660)	0	(143,445)
Preferred	0	0	0	(21,021)	0	(21,021)
Redemption of Series A and B preferred stock						0
Conversion of preferred stock	(1)	0	1	0	0	0
Additions to capital	4,479	109	146,362	0	0	150,950
Common share repurchases	0	(30)	(35,032)	0	0	(35,062)
Ending Balance at Dec. 31, 2012	188,992	962	1,367,199	(353,938)	293,910	1,497,125
Net income	0	0	0	126,487	0	126,487
Change in unrealized gain on mortgage securities, net	0	0	0	0	(101,001)	(101,001)
Amounts related to cash flow hedges, net	0	0	0	0	26,234	26,234
Cash dividends:
Common	0	0	(13,830)	(104,932)	0	(118,762)
Preferred	0	0	0	(17,536)	0	(17,536)
Redemption of Series A and B preferred stock	(187,109)	0	(19,924)	0	0	(207,033)
Conversion of preferred stock	(1,883)	2	1,881	0	0	0
Issuance of Series E preferred stock	165,756	0	0	0	0	165,756
Other capital stock transactions	0	0	1,752	53	0	1,805
Common share repurchases	0	(6)	(7,286)	0	0	(7,292)
Ending Balance at Dec. 31, 2013	$ 165,756	$ 958	$ 1,329,792	$ (349,866)	$ 219,143	$ 1,365,783