Loans and Leases - Summary of Payment Status of Loans Modified (Detail) $ in Millions	Dec. 31, 2023 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	$ 1,414
30-89 Days Past Due	123
Past Due 90 Days or More	49
Total	1,586
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	182
30-89 Days Past Due	7
Past Due 90 Days or More	9
Total	198
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	618
30-89 Days Past Due	21
Past Due 90 Days or More	12
Total	651
Residential Builder and Developer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	71
Total	71
Other Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	440
30-89 Days Past Due	48
Total	488
Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	93
30-89 Days Past Due	45
Past Due 90 Days or More	27
Total	165
Residential Limited Documentation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	9
30-89 Days Past Due	2
Past Due 90 Days or More	1
Total	12
Home Equity Lines and Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	1
Total	$ 1