Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities:
Net income (loss)	$ 1,619	$ (40,662)
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Decrease in accrued interest receivable	1,101	3,145
Decrease in accrued interest payable	(1,633)	(29)
Loss on derivative instruments, net	15,627	64,561
Loss on sale of investments, net	(5,417)	(4,238)
Fair value adjustments, net	(40)	(51)
Amortization of investment premiums, net	81,188	73,597
Other amortization and depreciation, net	682	850
Stock-based compensation expense	1,179	1,443
Decrease in other assets and liabilities, net	(2,120)	(881)
Net cash and cash equivalents provided by operating activities	103,020	106,211
Investing activities:
Purchase of investments	(282,943)	(4,970)
Principal payments received on investments	183,636	187,437
Proceeds from sales of investments	399,483	94,033
Principal payments received on mortgage loans held for investment, net	1,876	2,319
Distributions received from limited partnership	0	10,835
Net receipts (payments) on derivatives, including terminations	7,405	(26,092)
Other investing activities	(212)	(55)
Net cash and cash equivalents provided by investing activities	309,245	263,507
Financing activities:
Borrowings under repurchase agreements	39,007,126	11,394,652
Repayments of repurchase agreement borrowings and FHLB advances	(39,365,319)	(11,640,592)
Principal payments on non-recourse collateralized financing	(557)	(939)
Increase in restricted cash	20,608	32,489
Proceeds from issuance of preferred stock	18,212	0
Proceeds from issuance of common stock	139	77
Cash paid for stock issuance costs	(52)	0
Cash paid for repurchases of common stock	0	(310)
Payments related to tax withholding for stock-based compensation	(521)	(485)
Dividends paid	(23,942)	(26,670)
Net cash and cash equivalents used in financing activities	(385,522)	(306,756)
Net increase in cash and cash equivalents	26,743	62,962
Cash and cash equivalents at beginning of period	74,120	33,935
Cash and cash equivalents at end of period	100,863	96,897
Supplemental Disclosure of Cash Activity:
Cash paid for interest	$ 18,029	$ 12,476