Employee Benefit Plans (Disaggregated Information Related to Corporations Defined Benefit Pension Plans) (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 129,816	$ 130,900	$ 142,372	$ 143,944
Accumulated benefit obligation	129,816	130,900	142,372
Fair value of plan assets	174,207	169,727	174,611	$ 161,823
Funded status of the plan at end of year and accrued benefit (liability) recognized	44,391	38,827	$ 32,239
Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	119,198	120,179
Accumulated benefit obligation	119,198	120,179
Fair value of plan assets	174,207	169,727
Funded status of the plan at end of year and accrued benefit (liability) recognized	55,009	49,548
Restoration Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	10,618	10,721
Accumulated benefit obligation	10,618	10,721
Fair value of plan assets	0	0
Funded status of the plan at end of year and accrued benefit (liability) recognized	$ (10,618)	$ (10,721)