Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Operating activities:
Net income (loss)	$ 24,133	$ 46,510
Adjustments to reconcile net income to cash provided by operating activities:
Decrease (increase) in accrued interest receivable	(717)	(906)
(Decrease) increase in accrued interest payable	(1,056)	(462)
Provision for loan losses	0	261
Loss (gain) on derivative instruments, net	(31,654)	(12,683)
Loss (gain) on sale of investments, net	5,273	2,597
Fair value adjustments, net	162	(590)
Amortization of investment premiums, net	104,293	97,860
Other amortization and depreciation	7,007	4,398
Stock-based compensation expense	2,045	1,762
Other operating activities	3,708	3,907
Net cash and cash equivalents provided by operating activities	159,650	158,004
Investing activities:
Purchase of investments	457,008	1,325,082
Principal payments received on investments	404,464	742,551
Proceeds from sales of investments	376,278	327,962
Principal payments received on mortgage loans held for investment, net	14,150	10,775
Net payments on derivatives not designated as hedges	9,086	23,644
Other investing activities	8	(5,402)
Net cash and cash equivalents used in investing activities	328,790	(262,036)
Financing activities:
(Repayments of) borrowings under repurchase agreements, net	(430,743)	110,409
Principal payments on non-recourse collateralized financing	(1,753)	(9,502)
Increase in restricted cash	(19,370)	(15,849)
Proceeds from issuance of preferred stock	0	54,251
Proceeds from issuance of common stock	144	7,375
Cash paid for repurchases of common stock	0	5,965
Payments Related to tax withholding for share-based compensation	507	545
Dividends paid	48,902	52,343
Net cash and cash equivalents provided by (used in) financing activities	(501,131)	87,831
Net increase (decrease) in cash and cash equivalents	(12,691)	(16,201)
Cash and cash equivalents at beginning of period	69,330	55,809
Cash and cash equivalents at end of period	56,639	39,608
Supplemental Disclosure of Cash Activities:
Cash paid for interest	$ 15,703	$ 22,065