Employee and Retiree Benefit Plans (Components of Net Periodic Benefit Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2,129	$ 1,768	$ 4,258	$ 3,536
Interest cost	5,139	4,300	10,382	8,586
Expected return on plan assets	(7,954)	(6,155)	(16,092)	(12,288)
Amortization of prior service cost (credit)	579	156	1,179	312
Recognized actuarial loss (gain)	3,822	5,281	7,644	10,560
Net periodic benefit expense	3,715	5,350	7,371	10,706
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	292	327	584	653
Interest cost	574	521	1,148	1,042
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	(133)	0	(266)	0
Recognized actuarial loss (gain)	(78)	(8)	(155)	(15)
Net periodic benefit expense	$ 655	$ 840	$ 1,311	$ 1,680