Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities
Net loss	$ (71,165)	$ (34,535)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Net amortization of premium related to mortgage-backed securities	18,943	27,116
Reclassification of deferred swap net loss	1,376	13,438
Share-based compensation expense	1,293	1,045
Net realized gain on sale of securities	(4,287)	(16,453)
Net unrealized loss on MSR	38,111
Net unrealized gain on mortgage loans	(2,007)	(244)
Purchase of mortgage loans held for sale	(112,617)
Sale of mortgage loans held for sale	104,962
Net loss on derivative instruments	92,494	102,785
Other	(1,895)	29
Changes in operating assets and liabilities:
Decrease in accrued interest receivable	6,182	2,654
(Increase) decrease in other assets	11,241	(669)
Decrease in accrued interest payable	(1,886)	(3,956)
Increase in other liabilities	3,843	8,976
Net cash provided by operating activities	84,588	100,186
Investing activities
Purchases of securities	(217,728)	(783,566)
Principal repayments on securities	693,381	877,143
Sales of securities	1,540,791	628,123
Purchases of mortgage loans held for investment	(40,855)	(95,769)
Principal repayments on mortgage loans held for investment	24,870	4,172
Purchases of mortgage servicing rights	(84,361)
Net payments on derivative instruments	(15,402)	(25,050)
Net cash provided by investing activities	1,900,696	605,053
Financing activities
Repurchase of common stock	(14,776)
Cash dividends paid	(48,676)	(53,868)
Proceeds from borrowings	37,257,993	42,920,560
Principal repayments on borrowings	(39,293,135)	(43,571,853)
Proceeds from collateralized trust borrowing	6,240
Repayments on collateralized trust borrowing	(3,725)
Net cash used in financing activities	(2,096,079)	(705,161)
Net increase (decrease) in cash and cash equivalents	(110,795)	78
Cash and cash equivalents, beginning of period	816,715	627,595
Cash and cash equivalents, end of period	705,920	627,673
Supplemental disclosure of cash flow information
Cash paid for interest	28,667	39,226
Supplemental schedule of non-cash investing and financing activities
Obligation to brokers for unsettled purchases of securities	5,483	103,995
Receivable for securities sold	274,127	13,423
Dividends accrued not yet paid	47,166
Redeemable Preferred Stock
Supplemental schedule of non-cash investing and financing activities
Dividends accrued not yet paid	4,628	4,628
Common Stock
Supplemental schedule of non-cash investing and financing activities
Dividends accrued not yet paid	$ 42,538	$ 48,396