CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash Flows from Operating Activities
Net income (loss)	$ (90,000)	$ (1,674,352)	$ 364,101
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Amortization of mortgage-backed and credit risk transfer securities premiums and (discounts), net	37,397	15,980	46,243
Realized and unrealized (gain) loss on derivative instruments, net	(138,414)	859,097	570,595
Realized and unrealized (gain) loss on credit derivatives, net	0	41,635	12,490
(Gain) loss on investments, net	366,509	961,938	(624,466)
Increase (decrease) in provision for credit losses	(1,768)	1,768	0
(Gain) loss from investments in unconsolidated ventures in excess of distributions received	9	229	(490)
Other amortization	(21,383)	(23,276)	(23,207)
Net (gain) loss on extinguishment of debt	0	(14,742)	0
Changes in operating assets and liabilities:
(Increase) decrease in operating assets	(1,166)	51,645	(8,096)
Increase (decrease) in operating liabilities	1,108	(49,463)	6,189
Net cash provided by (used in) operating activities	152,292	170,459	343,359
Cash Flows from Investing Activities
Purchase of mortgage-backed and credit risk transfer securities	(17,132,975)	(13,613,447)	(9,244,391)
Distributions from (contributions to) investments in unconsolidated ventures, net	3,848	6,505	1,346
Change in other assets	0	40,846	10,327
Principal payments from mortgage-backed and credit risk transfer securities	825,189	892,592	2,189,327
Proceeds from sale of mortgage-backed and credit risk transfer securities	16,273,956	25,028,464	3,311,884
Payment on the sale of credit derivatives	0	(31,353)	0
Settlement (termination) of futures, forwards, swaps, swaptions and TBAs, net	156,160	(844,577)	(597,077)
Redemption of Federal Home Loan Bank of Indianapolis stock	0	74,250	0
Net change in due from counterparties and collateral held payable on derivative instruments	(5,430)	1,093	(3,174)
Principal payments from commercial loans held-for-investment	0	136	7,527
Net cash provided by (used in) investing activities	120,748	11,554,509	(4,324,231)
Cash Flows from Financing Activities
Proceeds from issuance of common stock	430,496	420,737	509,075
Redemption of preferred stock	(140,038)	0	0
Principal repayments of secured loans	0	(1,650,000)	0
Proceeds from repurchase agreements	82,347,113	75,698,735	131,624,461
Principal repayments of repurchase agreements and related fees	(82,587,978)	(85,987,597)	(127,694,642)
Net change in due from counterparties and collateral held payable on repurchase agreements	(4,743)	33,773	(32,557)
Payments of deferred costs	(354)	(35)	(346)
Payments of dividends	(133,068)	(137,499)	(271,234)
Net cash provided by (used in) financing activities	(88,572)	(11,621,886)	4,134,757
Net change in cash, cash equivalents and restricted cash	184,468	103,082	153,885
Cash, cash equivalents and restricted cash, beginning of period	392,584	289,502	135,617
Cash, cash equivalents and restricted cash, end of period	577,052	392,584	289,502
Supplement Disclosure of Cash Flow Information
Interest paid	10,363	149,230	489,661
Non-cash Investing and Financing Activities Information
Net change in unrealized gain (loss) on mortgage-backed and credit risk transfer securities	756	(207,708)	93,037
Dividends declared not paid	29,689	18,970	74,841
Increase (decrease) in Agency CMBS purchase commitments	0	(99,557)	(32,530)
Net change in investment related receivable (payable) excluding Agency CMBS purchase commitments	46	266	5,724
Change in foreign currency translation adjustment on other investments	75	(1,144)	1,158
Dividend paid in common stock	0	74,234	0
Offering costs not paid	$ 527	$ 0	$ 48