Loans, Leases, and Allowance for Credit Losses (Collateral-Dependent Loans) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost	$ 17	$ 7
Owner-occupied | Commercial | Hospital
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost	$ 12
Weighted average LTV	30.00%
Owner-occupied | Commercial | Land, Warehouse
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost		$ 2
Weighted average LTV		29.00%
Term | Commercial real estate | Hotel, Multi-family
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost	$ 5
Weighted average LTV	64.00%
Term | Commercial real estate | Multi-family
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost		$ 1
Weighted average LTV		55.00%
Home equity credit line | Consumer | Single family residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost		$ 1
Weighted average LTV		13.00%
1-4 family residential | Consumer | Single family residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Amortized cost		$ 3
Weighted average LTV		41.00%