Loans Held-for-Investment - Summary of TDRs by Type and Performing Status (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Troubled Debt Restructurings
TDR balance	$ 48	$ 54
Financing receivable, modifications, loans and leases receivable, allowance	8	10
TDR loans under fair value option	2	3
Consumer loans \| Residential first mortgage
Troubled Debt Restructurings
TDR balance	28	30
Consumer loans \| Home equity
Troubled Debt Restructurings
TDR balance	20	24
Performing
Troubled Debt Restructurings
TDR balance	38	44
Performing \| Consumer loans \| Residential first mortgage
Troubled Debt Restructurings
TDR balance	20	22
Performing \| Consumer loans \| Home equity
Troubled Debt Restructurings
TDR balance	18	22
Nonperforming
Troubled Debt Restructurings
TDR balance	10	10
Nonperforming \| Consumer loans \| Residential first mortgage
Troubled Debt Restructurings
TDR balance	8	8
Nonperforming \| Consumer loans \| Home equity
Troubled Debt Restructurings
TDR balance	$ 2	$ 2

The TDR loans held-for-investment carried under the fair value option method.

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Financing Receivable, Modifications, Loans and Leases Receivable, Allowance

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Amount of financing receivable modified as troubled debt restructuring.

+ 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=118936363&loc=SL6953676-111524

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-Section 50
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