CONSOLIDATED BALANCE SHEETS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Assets
Residential mortgage investments ($13.59 and $13.48 billion pledged under repurchase arrangements at March 31, 2015 and December 31, 2014, respectively)	$ 14,150,084	$ 13,908,104
Cash collateral receivable from interest rate swap counterparties	61,669	53,139
Interest rate swap agreements at fair value	285	1,657
Cash and cash equivalents	205,615	307,526
Receivables and other assets	114,229	118,643
Total Assets	14,531,882	14,389,069
Liabilities
Repurchase arrangements and similar borrowings	12,938,508	12,806,843
Interest rate swap agreements at fair value	37,791	27,034
Unsecured borrowings	100,000	100,000
Common stock dividend payable	30,701	34,054
Accounts payable and accrued expenses	28,583	30,367
Total Liabilities	13,135,583	12,998,298
Stockholders' equity
Common stock - $0.01 par value; 250,000 shares authorized: 95,812 and 95,848 shares issued and outstanding at March 31, 2015 and December 31, 2014, respectively	958	958
Paid-in capital	1,325,633	1,325,340
Accumulated deficit	(346,465)	(346,885)
Accumulated other comprehensive income	221,586	227,422
Stockholders' equity	1,396,299	1,390,771
Total Liabilities and Equity	14,531,882	14,389,069
Redeemable Preferred Stock [Member] | Cumulative Redeemable Preferred Stock, Series E [Member]
Stockholders' equity
Cumulative Preferred Stock	$ 194,587	$ 183,936