Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities:
Net Income	$ 68,069	$ 74,042	$ 39,812
Adjustments to reconcile net income to cash provided by operating activities:
Decrease (increase) in accrued interest receivable	(1,370)	10,464	6,504
(Decrease) increase in accrued interest payable	(347)	730	1,086
Provision for loan losses	261	192	871
Loss on derivative instruments, net	(10,076)	(908)	(2,825)
Gain on sale of investments, net	3,354	8,461	2,096
Loss on non-recourse collateralized financing	0	0	1,970
Fair value adjustments, net	(652)	735	2,149
Amortization and depreciation	136,608	90,530	32,505
Stock-based compensation expense	2,314	1,712	783
Net change in other assets and other liabilities	6,889	(934)	(1,538)
Net cash and cash equivalents provided by operating activities	208,760	149,388	70,641
Investing activities:
Purchase of investments	1,419,060	2,639,909	1,606,819
Principal payments received on investments	913,210	679,635	468,401
Proceeds from sales of investments	358,090	231,145	184,688
Principal payments received on securitized mortgage loans	15,828	40,830	37,556
Net payments on derivatives not designated as hedges	39,097	0	0
Other investing activities	(5,891)	2,893	(419)
Net cash and cash equivalents used in investing activities	(165,138)	(1,691,192)	(915,755)
Financing activities:
Borrowings under repurchase agreements, net	16,209	1,470,995	859,610
Deferred borrowing costs paid	0	825	0
Principal payments on non-recourse collateralized financing	(17,840)	(40,626)	(15,296)
Cash paid to redeem securitization financing bond	0	0	23,669
Increase in restricted cash	13,346	0	0
Proceeds from issuance of preferred stock	54,251	55,407	0
Proceeds from issuance of common stock	7,436	123,868	95,282
Cash paid for repurchases of common stock	6,934	921	0
Payments Related to Tax Withholding for Share-based Compensation	545	0	0
Dividends paid	69,332	59,061	40,873
Net cash and cash equivalents provided by (used in) financing activities	(30,101)	1,548,837	875,054
Net increase (decrease) in cash and cash equivalents	13,521	7,033	29,940
Cash and cash equivalents at beginning of period	55,809	48,776	18,836
Cash and cash equivalents at end of period	69,330	55,809	48,776
Supplemental Disclosure of Cash Activities:
Cash paid for interest	$ 33,517	$ 34,035	$ 22,110