Premises and Equipment - Year-End Premises and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 115,149	$ 125,374
Accumulated depreciation	(67,983)	(68,605)
Premises and equipment, net	47,166	56,769
Land and Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	8,303	8,392
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	40,494	40,418
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 66,352	$ 76,564