Loans Held-for-Investment - Summary of Newly Modified TDRs (Details) $ in Millions	12 Months Ended
Dec. 31, 2021 USD ($) loan	Dec. 31, 2020 USD ($) loan	Dec. 31, 2019 USD ($) loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| loan	12	14	14
Pre-Modification Unpaid Principal Balance	$ 4	$ 7	$ 1
Post-Modification Unpaid Principal Balance	$ 3	$ 7	$ 1
Residential first mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| loan	9	9	8
Pre-Modification Unpaid Principal Balance	$ 4	$ 2	$ 1
Post-Modification Unpaid Principal Balance	$ 3	$ 2	$ 1
Home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| loan	3	3	6
Pre-Modification Unpaid Principal Balance	$ 0	$ 0	$ 0
Post-Modification Unpaid Principal Balance	$ 0	$ 0	$ 0
Other consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| loan		1
Pre-Modification Unpaid Principal Balance		$ 0
Post-Modification Unpaid Principal Balance		$ 0
Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| loan		1
Pre-Modification Unpaid Principal Balance		$ 5
Post-Modification Unpaid Principal Balance		$ 5

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No definition available.

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524

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Amount, after troubled debt restructuring, of modified financing receivable.

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Amount, before troubled debt restructuring, of financing receivable to be modified.

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