Employee Benefit Plans (Disaggregated Information Related to Corporations Defined Benefit Pension Plans) (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 130,900	$ 142,372	$ 143,944	$ 185,925
Accumulated benefit obligation	130,900	142,372	143,944
Fair value of plan assets	169,727	174,611	161,823	$ 197,747
Funded status of the plan at end of year and accrued benefit (liability) recognized	38,827	32,239	$ 17,879
Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	120,179	130,750
Accumulated benefit obligation	120,179	130,750
Fair value of plan assets	169,727	174,611
Funded status of the plan at end of year and accrued benefit (liability) recognized	49,548	43,861
Restoration Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	10,721	11,622
Accumulated benefit obligation	10,721	11,622
Fair value of plan assets	0	0
Funded status of the plan at end of year and accrued benefit (liability) recognized	$ (10,721)	$ (11,622)