Loans and Leases (By Portfolio and Class) (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 51,098,642	$ 50,726,052
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	41,338,516	40,929,834
Commercial Portfolio Segment [Member] | Commercial non-mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	16,696,070	16,885,475
Commercial Portfolio Segment [Member] | Asset-based
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	1,492,886	1,557,841
Commercial Portfolio Segment [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	13,972,916	13,569,762
Commercial Portfolio Segment [Member] | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	7,896,586	7,587,970
Commercial Portfolio Segment [Member] | Equipment financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	1,280,058	1,328,786
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	9,760,126	9,796,218
Consumer Portfolio Segment [Member] | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	8,226,154	8,227,923
Consumer Portfolio Segment [Member] | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	1,479,420	1,516,955
Consumer Portfolio Segment [Member] | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 54,552	$ 51,340