Premises and equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment
Property, Plant and Equipment, Gross	$ 959,868	$ 998,899
Less - Accumulated depreciation and amortization	606,187	605,178
Subtotal	353,681	393,721
Construction in progress	158,587	81,288
Premises and equipment	601,787	565,284
Land
Property, Plant and Equipment
Property, Plant and Equipment, Gross	89,519	90,275
Building
Property, Plant and Equipment
Property, Plant and Equipment, Gross	$ 497,631	487,053
Building | Minimum
Property, Plant and Equipment
Property, Plant and Equipment, Useful Life	10 years
Building | Maximum
Property, Plant and Equipment
Property, Plant and Equipment, Useful Life	50 years
Equipment
Property, Plant and Equipment
Property, Plant and Equipment, Gross	$ 365,716	421,513
Equipment | Minimum
Property, Plant and Equipment
Property, Plant and Equipment, Useful Life	2 years
Equipment | Maximum
Property, Plant and Equipment
Property, Plant and Equipment, Useful Life	10 years
Leasehold improvements
Property, Plant and Equipment
Property, Plant and Equipment, Gross	$ 96,521	$ 90,333
Leasehold improvements | Minimum
Property, Plant and Equipment
Property, Plant and Equipment, Useful Life	3 years
Leasehold improvements | Maximum
Property, Plant and Equipment
Property, Plant and Equipment, Useful Life	10 years