Employee Benefits - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Benefits
Net periodic benefit cost
Service cost	$ 4,481	$ 12,082	$ 10,829
Interest cost	7,730	6,911	8,266
Expected return on plan assets	(18,891)	(16,807)	(13,539)
Amortization of prior service cost	(3,280)	(3,237)	0
Special event plan closure	0	0	0
Amortization of net loss	777	3,995	3,914
Net periodic benefit cost	(9,183)	2,944	9,470
Post-retirement Benefits
Net periodic benefit cost
Service cost	0	148	1,728
Interest cost	2	72	1,014
Expected return on plan assets	0	0	0
Amortization of prior service cost	(15,085)	(14,490)	(8,084)
Special event plan closure	(26)	(20,177)	0
Amortization of net loss	2,824	2,607	375
Net periodic benefit cost	$ (12,285)	$ (31,840)	$ (4,967)