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Commitments and Contingencies - Contractual Commitments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Agency Business Commitments
Restricted cash	$ 704,844	$ 517,090	$ 713,808	$ 486,690
Total
2023 (nine months ending December 31, 2023)	1,951,731
2024	3,006,520
2025	1,911,367
2026	4,915,290
2027	993,582
2028	187,301
Thereafter	174,827
Total	13,140,618
Operating lease expense	2,600	$ 2,400
Unfunded CLO Commitments
Unfunded commitments related to structured loans and investments	1,050,000
Fannie Mae Mortgage
Agency Business Commitments
Minimum liquid assets to be maintained to meet operational liquidity requirements	$ 18,800
Period of funding for collateral requirement	48 months
Forward Contracts
Agency Business Commitments
Period of contractual commitment	60 days
Restricted liquidity arrangement - loans sold under the Fannie Mae DUS program \| Fannie Mae Mortgage
Agency Business Commitments
Letter of credit required	$ 67,300
Letter of credit assigned	64,000
Restricted cash	2,500
Reserve required to fund additional restricted liquidity over the next 48 months	$ 35,700
Period of additional funding for collateral requirement	48 months
Cash collateral arrangement - purchase and loss obligations under Freddie Mac's SBL Program
Agency Business Commitments
Cash collateral per securitization	$ 5,000
Outstanding letters of credit	5,000
Minimum capital arrangement - Seller/servicer agreements with secondary market investors
Minimum Annual Operating Lease Payments
2023 (nine months ending December 31, 2023)	7,076
2024	9,180
2025	9,318
2026	9,363
2027	7,929
2028	7,301
Thereafter	20,491
Total	70,658
Loss sharing arrangement
Debt Obligations
2023 (nine months ending December 31, 2023)	1,944,655
2024	2,997,340
2025	1,902,049
2026	4,905,927
2027	985,653
2028	180,000
Thereafter	154,336
Total	$ 13,069,960