CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash Flows from Operating Activities
Net income (loss)	$ (25,353)	$ (1,797,065)
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	28,436	9,821
Realized and unrealized (gain) loss on derivative instruments, net	(149,255)	919,605
Realized and unrealized (gain) loss on credit derivatives, net	0	41,635
(Gain) loss on investments, net	276,067	996,743
Increase (decrease) in provision for credit losses	(1,768)	0
(Gain) loss from investments in unconsolidated ventures in excess of distributions received	4	245
Other amortization	(15,906)	(17,424)
Net (gain) loss on extinguishment of debt	0	(14,742)
Changes in operating assets and liabilities:
(Increase) decrease in operating assets	(2,904)	53,921
Increase (decrease) in operating liabilities	1,134	(49,027)
Net cash provided by operating activities	110,455	143,712
Cash Flows from Investing Activities
Purchase of mortgage-backed and credit risk transfer securities	(13,387,052)	(10,515,245)
Distributions from investments in unconsolidated ventures, net	4,142	2,267
Change in other assets	0	40,846
Principal payments from mortgage-backed and credit risk transfer securities	615,203	730,330
Proceeds from sale of mortgage-backed and credit risk transfer securities	11,815,848	24,265,520
Payment on the sale of credit derivatives	0	(31,353)
Settlement (termination) of forwards, swaps, swaptions and TBAs, net	164,396	(909,435)
Redemption of Federal Home Loan Bank of Indianapolis stock	0	74,250
Net change in due from counterparties and collateral held payable on derivative instruments	(10,167)	(1,110)
Principal payments from commercial loans held-for-investment	0	136
Net cash provided by (used in) investing activities	(797,630)	13,656,206
Cash Flows from Financing Activities
Proceeds from issuance of common stock	375,283	347,182
Redemption of preferred stock	(140,038)	0
Principal repayments of secured loans	0	(1,650,000)
Proceeds from repurchase agreements	71,066,670	55,623,982
Principal repayments of repurchase agreements and related fees	(70,421,571)	(67,898,255)
Net change in due from counterparties and collateral held payable on repurchase agreements	(2,311)	30,123
Payments of deferred offering costs	(575)	(29)
Payments of dividends	(96,618)	(117,325)
Net cash provided by (used in) financing activities	780,840	(13,664,322)
Net change in cash, cash equivalents and restricted cash	93,665	135,596
Cash, cash equivalents and restricted cash, beginning of period	392,584	289,502
Cash, cash equivalents and restricted cash, end of period	486,249	425,098
Supplement Disclosure of Cash Flow Information
Interest paid	8,283	145,935
Non-cash Investing and Financing Activities Information
Net change in unrealized gain (loss) on mortgage-backed and credit risk transfer securities	1,663	(199,940)
Dividends declared not paid	28,057	11,781
Increase (decrease) in Agency CMBS purchase commitments	0	(99,557)
Net change in investment related receivable (payable) excluding Agency CMBS purchase commitments	61	328
Dividend paid in common stock	0	74,234
Offering costs not paid	(351)	(78)
Change in foreign currency translation adjustment on other investments	$ (164)	$ (489)