CONSOLIDATED BALANCE SHEETS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012		Sep. 30, 2013 Cumulative Preferred Stock, Series A [Member]	Dec. 31, 2012 Cumulative Preferred Stock, Series A [Member]	Sep. 30, 2013 Convertible Preferred Stock [Member] Cumulative Convertible Preferred Stock, Series B [Member]	Dec. 31, 2012 Convertible Preferred Stock [Member] Cumulative Convertible Preferred Stock, Series B [Member]	Sep. 30, 2013 Redeemable Preferred Stock [Member] Cumulative Redeemable Preferred Stock, Series E [Member]	Dec. 31, 2012 Redeemable Preferred Stock [Member] Cumulative Redeemable Preferred Stock, Series E [Member]
Assets
Residential mortgage investments ($13.29 and $13.45 billion pledged under repurchase arrangements at September 30, 2013 and December 31, 2012, respectively)	$ 13,738,311	[1]	$ 13,860,158	[1]
Cash collateral receivable from interest rate swap counterparties	27,829		49,972
Interest rate swap agreements at fair value	1,558		169
Cash and cash equivalents	235,102		425,445
Receivables and other assets	132,993		130,402
Investments in unconsolidated affiliates	3,117		3,117
Total Assets	14,138,910		14,469,263
Liabilities
Repurchase arrangements and similar borrowings	12,618,571		12,784,238
Interest rate swap agreements at fair value	11,425		32,868
Unsecured borrowings	103,095		103,095
Common stock dividend payable	30,662		29,512
Accounts payable and accrued expenses	22,061		22,425
Total Liabilities	12,785,814		12,972,138
Stockholders' equity
Cumulative Preferred Stock					0	2,604	0	186,388	164,310	0
Common stock-$0.01 par value; 250,000 shares authorized: 95,761 and 96,229 shares issued and outstanding at September 30, 2013 and December 31, 2012, respectively	957		962
Paid-in capital	1,329,124		1,367,199
Accumulated deficit	(353,852)		(353,938)
Accumulated other comprehensive income	212,557		293,910
Stockholders' Equity Attributable to Parent	1,353,096		1,497,125
Total Liabilities and Equity	$ 14,138,910		$ 14,469,263

[1] Includes unrealized gains and losses for residential mortgage investments classified as available-for-sale (see NOTE 10).