Loans Subject to Repurchase from Ginnie Mae (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans subject to repurchase from Ginnie Mae	$ 1,575	$ 1,496
Financial Asset, Equal to or Greater than 90 Days Past Due \| Payment Deferral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans subject to repurchase from Ginnie Mae	$ 1,403	$ 1,301

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