Loans and Leases (By Portfolio and Class) (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 51,626,048	$ 49,764,426
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	41,878,482	40,103,951
Commercial Portfolio Segment [Member] | Commercial non-mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	17,255,036	16,392,795
Commercial Portfolio Segment [Member] | Asset-based
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	1,718,251	1,821,642
Commercial Portfolio Segment [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	13,542,251	12,997,163
Commercial Portfolio Segment [Member] | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	7,118,820	6,621,982
Commercial Portfolio Segment [Member] | Equipment financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	1,535,564	1,628,393
Commercial Portfolio Segment [Member] | Warehouse lending
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	708,560	641,976
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	9,747,566	9,660,475
Consumer Portfolio Segment [Member] | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	8,140,182	7,963,420
Consumer Portfolio Segment [Member] | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	1,552,850	1,633,107
Consumer Portfolio Segment [Member] | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 54,534	$ 63,948