Credit Quality and the Allowance for Loan and Lease Losses - Summary of Amortized Cost Basis of Loans Modified for Borrowers Experiencing Financial Difficulty (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 202
Commercial
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 163
% of Total Class	0.21%
Commercial | Term Extension
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 159
Commercial | Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	1
Commercial | Term Extension and Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	3
Commercial | Commercial and industrial loans
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 106
% of Total Class	0.18%
Commercial | Commercial and industrial loans | Term Extension
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 105
Commercial | Commercial and industrial loans | Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	1
Commercial | Commercial and industrial loans | Term Extension and Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	0
Commercial | Commercial mortgage owner-occupied loans
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 1
% of Total Class	0.02%
Commercial | Commercial mortgage owner-occupied loans | Term Extension
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 1
Commercial | Commercial mortgage owner-occupied loans | Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	0
Commercial | Commercial mortgage owner-occupied loans | Term Extension and Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	0
Commercial | Commercial mortgage nonowner-occupied loans
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 25
% of Total Class	0.43%
Commercial | Commercial mortgage nonowner-occupied loans | Term Extension
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 22
Commercial | Commercial mortgage nonowner-occupied loans | Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	0
Commercial | Commercial mortgage nonowner-occupied loans | Term Extension and Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	3
Commercial | Commercial construction loans
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 31
% of Total Class	0.56%
Commercial | Commercial construction loans | Term Extension
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 31
Commercial | Commercial construction loans | Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	0
Commercial | Commercial construction loans | Term Extension and Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	0
Residential Mortgage
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 24
% of Total Class	0.14%
Residential Mortgage | Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 8
% of Total Class	0.05%
Residential Mortgage | Term Extension and Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 14
% of Total Class	0.08%
Residential Mortgage | Term Extension, Interest Rate Reduction and Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 2
% of Total Class	0.01%
Consumer
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 15
% of Total Class	0.05%
Consumer | Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 10
Consumer | Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	1
Consumer | Term Extension and Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	1
Consumer | Term Extension, Interest Rate Reduction and Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	3
Consumer | Home equity
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 4
% of Total Class	0.10%
Consumer | Home equity | Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 0
Consumer | Home equity | Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	0
Consumer | Home equity | Term Extension and Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	1
Consumer | Home equity | Term Extension, Interest Rate Reduction and Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	3
Consumer | Credit card
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 10
% of Total Class	0.57%
Consumer | Credit card | Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 10
Consumer | Credit card | Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	0
Consumer | Credit card | Term Extension and Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	0
Consumer | Credit card | Term Extension, Interest Rate Reduction and Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	0
Consumer | Other consumer loans
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 1
% of Total Class	0.02%
Consumer | Other consumer loans | Interest Rate Reduction
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 0
Consumer | Other consumer loans | Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	1
Consumer | Other consumer loans | Term Extension and Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	0
Consumer | Other consumer loans | Term Extension, Interest Rate Reduction and Payment Deferral
Financing Receivable, Modifications
Financing receivable, excluding accrued interest, modified in period, amount	$ 0