Asset Quality - Schedule of Breakdown of Nonperforming TDRs by Loans Category (Details) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2023 loan	Dec. 31, 2022 USD ($) loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan	136	4,205
Pre-modification Outstanding Recorded Investment		$ 334
Post-modification Outstanding Recorded Investment		$ 236
Prior-Year Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		2,965
Pre-modification Outstanding Recorded Investment		$ 156
Post-modification Outstanding Recorded Investment		$ 118
Prior-Year Accruing \| Total commercial loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		19
Pre-modification Outstanding Recorded Investment		$ 0
Post-modification Outstanding Recorded Investment		$ 0
Prior-Year Accruing \| Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		2,946
Pre-modification Outstanding Recorded Investment		$ 156
Post-modification Outstanding Recorded Investment		$ 118
Non-performing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		1,240
Pre-modification Outstanding Recorded Investment		$ 178
Post-modification Outstanding Recorded Investment		$ 118
Non-performing Loans \| Total commercial loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		31
Pre-modification Outstanding Recorded Investment		$ 110
Post-modification Outstanding Recorded Investment		$ 58
Non-performing Loans \| Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		1,209
Pre-modification Outstanding Recorded Investment		$ 68
Post-modification Outstanding Recorded Investment		$ 60
Total commercial real estate loans \| Prior-Year Accruing \| Total commercial real estate loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		0
Pre-modification Outstanding Recorded Investment		$ 0
Post-modification Outstanding Recorded Investment		$ 0
Total commercial real estate loans \| Non-performing Loans \| Total commercial real estate loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		4
Pre-modification Outstanding Recorded Investment		$ 50
Post-modification Outstanding Recorded Investment		$ 13
Commercial and industrial \| Prior-Year Accruing \| Total commercial loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		19
Pre-modification Outstanding Recorded Investment		$ 0
Post-modification Outstanding Recorded Investment		$ 0
Commercial and industrial \| Non-performing Loans \| Total commercial loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		27
Pre-modification Outstanding Recorded Investment		$ 60
Post-modification Outstanding Recorded Investment		$ 45
Commercial mortgage \| Prior-Year Accruing \| Total commercial real estate loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		0
Pre-modification Outstanding Recorded Investment		$ 0
Post-modification Outstanding Recorded Investment		$ 0
Commercial mortgage \| Non-performing Loans \| Total commercial real estate loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		4
Pre-modification Outstanding Recorded Investment		$ 50
Post-modification Outstanding Recorded Investment		$ 13
Real estate — residential mortgage \| Prior-Year Accruing \| Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		425
Pre-modification Outstanding Recorded Investment		$ 41
Post-modification Outstanding Recorded Investment		$ 35
Real estate — residential mortgage \| Non-performing Loans \| Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		238
Pre-modification Outstanding Recorded Investment		$ 30
Post-modification Outstanding Recorded Investment		$ 27
Home equity loans \| Prior-Year Accruing \| Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		1,547
Pre-modification Outstanding Recorded Investment		$ 96
Post-modification Outstanding Recorded Investment		$ 73
Home equity loans \| Non-performing Loans \| Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		468
Pre-modification Outstanding Recorded Investment		$ 32
Post-modification Outstanding Recorded Investment		$ 28
Consumer direct loans \| Prior-Year Accruing \| Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		272
Pre-modification Outstanding Recorded Investment		$ 4
Post-modification Outstanding Recorded Investment		$ 3
Consumer direct loans \| Non-performing Loans \| Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		156
Pre-modification Outstanding Recorded Investment		$ 2
Post-modification Outstanding Recorded Investment		$ 2
Credit cards \| Prior-Year Accruing \| Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		607
Pre-modification Outstanding Recorded Investment		$ 4
Post-modification Outstanding Recorded Investment		$ 2
Credit cards \| Non-performing Loans \| Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		331
Pre-modification Outstanding Recorded Investment		$ 2
Post-modification Outstanding Recorded Investment		$ 2
Consumer indirect loans \| Prior-Year Accruing \| Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		95
Pre-modification Outstanding Recorded Investment		$ 11
Post-modification Outstanding Recorded Investment		$ 5
Consumer indirect loans \| Non-performing Loans \| Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans \| loan		16
Pre-modification Outstanding Recorded Investment		$ 2
Post-modification Outstanding Recorded Investment		$ 1

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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