Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Service cost, net	$ 3,714	$ 5,191	$ 7,400	$ 10,597
Interest cost on projected benefit obligations	6,180	2,169	12,318	4,405
Expected return on plan assets	(10,028)	(10,570)	(19,978)	(21,541)
Recognition of prior service cost	(1,079)	(1,064)	(2,148)	(2,178)
Recognition of actuarial losses/(gains)	3,108	5,286	6,193	10,793
Net periodic pension cost/(credit)	1,895	1,012	3,785	2,076
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost, net	289	416	579	832
Interest cost on projected benefit obligations	1,256	674	2,511	1,348
Expected return on plan assets	(1,383)	(1,547)	(2,766)	(3,094)
Recognition of prior service cost	0	0	0	0
Recognition of actuarial losses/(gains)	548	585	1,096	1,169
Net periodic pension cost/(credit)	710	128	1,420	255
Other Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost, net	3,425	4,775	6,821	9,765
Interest cost on projected benefit obligations	4,916	1,492	9,792	3,051
Expected return on plan assets	(8,645)	(9,023)	(17,212)	(18,447)
Recognition of prior service cost	(1,060)	(1,045)	(2,110)	(2,141)
Recognition of actuarial losses/(gains)	2,561	4,709	5,098	9,639
Net periodic pension cost/(credit)	1,197	908	2,389	1,867
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year, Description	27,500		27,500
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost, net	0	0	0	0
Interest cost on projected benefit obligations	8	3	15	6
Expected return on plan assets	0	0	0	0
Recognition of prior service cost	(19)	(19)	(38)	(37)
Recognition of actuarial losses/(gains)	(1)	(8)	(1)	(15)
Net periodic pension cost/(credit)	$ (12)	$ (24)	$ (24)	$ (46)