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Commitments and Contingencies, Contractual Commitments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Agency Business Commitments
Cash collateral	$ 486,690	$ 197,470	$ 210,875	$ 180,606
Debt Obligations
2022	3,360,731
2023	1,886,918
2024	2,925,345
2025	1,109,257
2026	2,210,054
Thereafter	640,185
Total	12,132,490
Minimum Annual Operating Lease Payments
2022	8,342
2023	8,067
2024	7,929
2025	7,978
2026	8,282
Thereafter	26,098
Total	66,696
Total
2022	3,369,073
2023	1,894,985
2024	2,933,274
2025	1,117,235
2026	2,218,336
Thereafter	666,283
Total	$ 12,199,186
Operating Lease, Weighted average remaining lease term (in years)	8 years 2 months 12 days	9 years
Operating Lease, Weighted average discount rate (as a percent)	4.00%	4.90%
Operating lease expense	$ 9,300	$ 6,200	$ 6,100
Unfunded CLO Commitments
Unfunded commitments related to structured loans and investments	975,200
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
Minimum
Total
Remaining lease term	1 month 6 days	6 months
Maximum
Total
Remaining lease term	9 years	10 years
Restricted liquidity arrangement - loans sold under the Fannie Mae DUS program \| Fannie Mae Mortgage
Agency Business Commitments
Letter of credit assigned	$ 45,000
Cash collateral	18,700
Reserve required to fund additional restricted liquidity over the next 48 months	$ 43,000
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