Employee Benefits (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Pension Plan
Net periodic benefit cost
Service cost	$ 1,120	$ 3,020	$ 2,240	$ 6,040
Interest cost	1,933	1,728	3,865	3,456
Expected return on plan assets	(4,723)	(4,202)	(9,445)	(8,404)
Amortization of prior service credit	(820)	(809)	(1,640)	(1,618)
Amortization of net loss	194	999	388	1,998
Special event plan closure	0	0	0	0
Net periodic benefit cost	(2,296)	736	(4,591)	1,472
Estimated 2021 pension plan contribution, disclosed in prior year 10K					$ 4,000
Contribution by employer in 2022			2,000
Postretirement Benefit Plan
Net periodic benefit cost
Service cost	0	0	0	148
Interest cost	1	1	1	70
Expected return on plan assets	0	0	0	0
Amortization of prior service credit	(3,771)	(3,765)	(7,543)	(6,962)
Amortization of net loss	706	705	1,412	1,197
Special event plan closure	0	0	0	(20,177)
Net periodic benefit cost	$ (3,064)	$ (3,059)	$ (6,129)	$ (25,724)