Loans and Leases - Collateral-Dependent Loans Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 61,292	$ 58,102
Financing receivable, allowance for credit loss, writeoff, collateral	1	2
Commercial | Collateral Pledged
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	250	124
Commercial | C&I
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	32,633	31,781
Commercial | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	14,216	13,228
C&I | Asset Pledged as Collateral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, allowance for credit loss, writeoff, collateral	144	10
C&I | Commercial | C&I
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	30,614	29,523
C&I | Commercial | C&I | Collateral Pledged
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	117
CRE | Commercial | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	14,216	13,228
CRE | Commercial | Commercial real estate | Collateral Pledged
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	133
HELOC | Asset Pledged as Collateral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	6	7
Real estate installment loans | Asset Pledged as Collateral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 27	$ 26