Employee and Retiree Benefit Plans (Components of Net Periodic Benefit Expense) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2,129	$ 1,768
Interest cost	5,243	4,286
Expected return on plan assets	(8,138)	(6,133)
Amortization of prior service cost (credit)	600	156
Recognized actuarial loss	3,822	5,279
Net periodic benefit expense	3,656	5,356
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	292	326
Interest cost	574	521
Expected return on plan assets	0	0
Amortization of prior service cost (credit)	(133)	0
Recognized actuarial loss	(77)	(7)
Net periodic benefit expense	$ 656	$ 840