CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities
Net income (loss)	$ 1,726,420	$ 2,396,280	$ (889,772)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities
Amortization of premiums and discounts of investments, net	87,154	784,110	1,371,178
Amortization of securitized debt premiums and discounts and deferred financing costs	(4,733)	(6,620)	(11,576)
Depreciation, amortization and other noncash expenses	20,506	24,636	41,357
Net (gains) losses on investments and derivatives	109,443	(1,204,830)	1,707,366
Business divestiture-related (gains) losses	40,258	278,559	0
Income (loss) from unconsolidated joint ventures	(11,454)	12,181	7,072
Loan loss provision (reversal)	(20,660)	(145,066)	147,581
Payments on purchases of loans held for sale	0	(51,403)	(147,833)
Proceeds from sales and repayments of loans held for sale	4,597	90,020	168,716
Net receipts (payments) on derivatives	3,643,954	932,867	(1,958,131)
Net change in
Other assets	(11,437)	31,044	249,778
Interest receivable	(403,613)	32,926	159,320
Interest payable	233,753	(99,590)	(285,219)
Other liabilities	(41,777)	1,725	(31,870)
Net cash provided by (used in) operating activities	5,372,411	3,076,839	527,967
Cash flows from investing activities
Payments on purchases of securities	(45,474,466)	(22,344,751)	(32,676,856)
Proceeds from sales of securities	25,055,929	11,670,321	52,639,778
Principal payments on securities	9,541,036	18,742,951	19,571,476
Payments on purchases and origination of loans	(6,137,067)	(7,715,200)	(2,257,314)
Proceeds from sales of loans	1,930,367	1,213,745	624,026
Principal payments on loans	1,562,308	2,610,912	2,222,500
Payments on purchases of MSR	(1,009,349)	(473,035)	0
Proceeds from sales of MSR	9,085	82,175	72,160
Payments on purchases of interests in MSR	(4,913)	(65,107)	0
Investments in real estate	0	(2,329)	(7,450)
Proceeds from sales of real estate	0	53,910	149,600
Proceeds from reverse repurchase agreements	24,500,024	16,734,313	58,800,000
Payments on reverse repurchase agreements	(24,500,024)	(16,734,313)	(58,800,000)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	0	290	7,590
Proceeds from sale of equity securities	0	6,957	0
Cash acquired (paid) in asset acquisition	0	0	6,264
Net proceeds from business divestiture	0	1,118,440	0
Net cash provided by (used in) investing activities	(14,527,070)	4,899,279	40,351,774
Cash flows from financing activities
Proceeds from repurchase agreements and other secured financing	3,571,043,066	2,288,704,788	2,776,331,362
Payments on repurchase agreements and other secured financing	(3,566,953,367)	(2,298,775,005)	(2,816,805,618)
Proceeds from issuances of securitized debt	5,473,311	3,719,027	2,385,374
Principal payments on securitized debt	(1,234,090)	(1,716,196)	(1,238,962)
Payments on purchases of securitized debt	(8,495)	0	0
Payment of deferred financing cost	0	(9,279)	(553)
Net proceeds from stock offerings, direct purchases and dividend reinvestments	2,636,000	552,215	1,175
Redemptions of preferred stock	0	0	(460,000)
Proceeds from participations issued	1,908,204	1,847,821	38,741
Payments on repurchases of participations issued	(1,973,666)	(818,575)	0
Principal payments on participations issued	(50,712)	(23,374)	0
Net principal receipts (payments) on mortgages payable	0	(2,237)	(60,980)
Net contributions (distributions) from (to) noncontrolling interests	72,389	5,635	7,762
Net payments on share repurchase	0	0	(209,418)
Settlement of stock-based awards in satisfaction of withholding tax requirements	(4,108)	(2,830)	0
Dividends paid	(1,519,249)	(1,359,721)	(1,475,650)
Net cash provided by (used in) financing activities	9,389,283	(7,877,731)	(41,486,767)
Net (decrease) increase in cash and cash equivalents	234,624	98,387	(607,026)
Cash and cash equivalents including cash pledged as collateral, beginning of period	1,342,090	1,243,703	1,850,729
Cash and cash equivalents including cash pledged as collateral, end of period	1,576,714	1,342,090	1,243,703
Supplemental disclosure of cash flow information
Interest received	2,459,012	2,701,381	3,681,826
Dividends received	0	51	4,643
Interest paid (excluding interest paid on interest rate swaps)	866,829	269,244	1,166,977
Net interest received (paid) on interest rate swaps	15,621	(340,738)	296,621
Taxes received (paid)	(492)	(3,797)	1,515
Noncash investing and financing activities
Receivable for unsettled trades	575,091	2,656	15,912
Payable for unsettled trades	1,157,846	147,908	884,069
Net change in unrealized gains (losses) on available-for-sale securities, net of reclassification adjustment	(4,667,306)	(2,415,925)	1,236,144
Dividends declared, not yet paid	412,113	321,142	307,613
Derecognition of assets of consolidated VIEs	424,005	3,075,961	1,222,221
Derecognition of securitized debt of consolidated VIEs	391,928	2,506,799	1,141,311
Derecognition of mortgages payable	$ 0	$ 314,485	$ 0