Retirement Plans and Other Postretirement Benefits - Schedule of Net Periodic Benefit Costs and Portion including Portion Charged to Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Amortization of:
Portion of costs (credits) charged to expense	$ (2,777)	$ (12,188)	$ (9,427)	$ (36,633)
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefits earned during the period	11,038	10,910	33,114	32,731
Non-service costs (credits):
Interest cost on benefit obligation	38,780	37,161	116,340	111,482
Expected return on plan assets	(44,698)	(47,163)	(134,094)	(141,488)
Amortization of:
Prior service credit	0	0	0	0
Net actuarial loss (gain)	11,683	10,479	35,049	31,437
Net periodic benefit costs (credits)	16,803	11,387	50,409	34,162
Portion of costs (credits) charged to expense	10,270	5,828	30,096	17,665
Other Benefits Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefits earned during the period	2,020	2,489	6,061	7,466
Non-service costs (credits):
Interest cost on benefit obligation	5,086	5,542	15,258	16,627
Expected return on plan assets	(12,142)	(11,709)	(36,426)	(35,126)
Amortization of:
Prior service credit	0	(9,447)	(1,265)	(28,341)
Net actuarial loss (gain)	(2,932)	(2,169)	(8,796)	(6,507)
Net periodic benefit costs (credits)	(7,968)	(15,294)	(25,168)	(45,881)
Portion of costs (credits) charged to expense	$ (6,110)	$ (11,396)	$ (19,382)	$ (34,217)