Loans and Leases (By Portfolio and Class) (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 45,646,743	$ 22,271,729
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	36,662,265	15,179,966
Commercial | Commercial non-mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	13,935,450	6,882,480
Commercial | Asset-based
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	1,892,278	1,067,248
Commercial | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	12,365,451	5,463,321
Commercial | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	5,776,219	1,139,859
Commercial | Equipment financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	1,778,326	627,058
Commercial | Warehouse lending
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	914,541	0
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	8,984,478	7,091,763
Consumer | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	7,223,728	5,412,905
Consumer | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	1,681,610	1,593,559
Consumer | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 79,140	$ 85,299