Premises and Equipment (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Depreciation	$ 61,900	$ 60,600	$ 57,400
Operating Lease, Rent Expense	49,700	50,500	47,700
Operating Lease, Right-of-Use Asset	270,282	280,502
Operating lease, payments	33,700	32,100
Premises and Equipment
Property, Plant and Equipment [Line Items]
Operating Lease, Right-of-Use Asset	270,300	280,500
Other Liabilities [Member]
Property, Plant and Equipment [Line Items]
Operating lease, liability	308,053	316,400
Partnership Interest [Member]
Property, Plant and Equipment [Line Items]
Operating Lease, Rent Expense	$ 349	$ 337	$ 327