Pension Plans and Other Postretirement Benefits - Net Periodic Defined Benefit Cost for Defined Benefit Plans (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2,000	$ 2,000
Interest cost on projected benefit obligation	27,000	29,000
Expected return on plan assets	(46,000)	(51,000)
Amortization of net actuarial gain	(1,000)	0
Net periodic benefit	$ (18,000)	$ (20,000)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other costs of operations	Other costs of operations
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0
Interest cost on projected benefit obligation	1,000	1,000
Expected return on plan assets	0	0
Amortization of net actuarial gain	(1,000)	(1,000)
Net periodic benefit	$ 0	$ 0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other costs of operations	Other costs of operations