Organization, Basis of Presentation and Summary of Significant Accounting Policies - Loans Eligible for Repurchase (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2022	Dec. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans at fair value	$ 5,208,167	$ 17,473,324
Gnnie Mae
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans at fair value	391,100	563,400
Loans, fair value	384,000	555,100
Loans, fair value adjustment	$ (7,100)	$ 8,300

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-URI http://asc.fasb.org/subtopic&trid=2196772

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