Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Operating activities:
Net income (loss)	$ (9,472)	$ (734)
Adjustments to reconcile net income to cash provided by operating activities:
Decrease (increase) in accrued interest receivable	(1,699)	(1,684)
(Decrease) increase in accrued interest payable	313	298
Loss (gain) on derivative instruments, net	25,323	13,422
Loss (gain) on sale of investments, net	(1,308)	3,307
Fair value adjustments, net	(39)	(32)
Amortization of investment premiums, net	36,640	31,968
Other amortization and depreciation	1,521	2,861
Stock-based compensation expense	693	672
Other operating activities	(1,014)	(175)
Net cash and cash equivalents provided by operating activities	50,958	49,903
Investing activities:
Purchase of investments	(386,660)	(127,552)
Principal payments received on investments	102,033	128,676
Proceeds from sales of investments	102,923	59,799
Principal payments received on mortgage loans held for investment, net	6,984	1,605
Investment in limited partnership	(6,000)	0
Net payments on derivatives not designated as hedges	6,405	2,542
Other investing activities	(75)	(5)
Net cash and cash equivalents used in investing activities	(187,200)	59,981
Financing activities:
(Repayments of) borrowings under repurchase agreements, net	172,733	(95,314)
Principal payments on non-recourse collateralized financing	(603)	(527)
Increase in restricted cash	(24,704)	(4,857)
Proceeds from issuance of common stock	30	114
Cash paid for repurchases of common stock	(131)	0
Payments Related to tax withholding for share-based compensation	(545)	(505)
Dividends paid	(15,978)	(16,957)
Net cash and cash equivalents provided by (used in) financing activities	130,802	(118,046)
Net increase (decrease) in cash and cash equivalents	(5,440)	(8,162)
Cash and cash equivalents at beginning of period	43,944	69,330
Cash and cash equivalents at end of period	38,504	61,168
Supplemental Disclosure of Cash Activities:
Cash paid for interest	$ 3,989	$ 4,935