Pensions and Other Postretirement Benefit Plans (Schedule of Funded Status of Plans and Composition of Accrued Pension Cost) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Noncurrent asset	$ 32,500	$ 31,100
Pension plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	225,327	239,051	$ 211,755
Benefit obligation	230,790	245,800	227,211
Funded status	(5,463)	(6,749)
Noncurrent asset	32,504	31,139
Current liability	(7,116)	(2,281)
Noncurrent liability	(30,851)	(35,607)
Net amount recognized	(5,463)	(6,749)
Net actuarial loss	52,138	53,065
Prior service cost/(credit)	256	393
Net amount recognized	52,394	53,458
Other postretirement benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0	0
Benefit obligation	44,884	47,977	$ 54,384
Funded status	(44,884)	(47,977)
Noncurrent asset	0	0
Current liability	(3,627)	(3,660)
Noncurrent liability	(41,257)	(44,317)
Net amount recognized	(44,884)	(47,977)
Net actuarial loss	17,483	20,736
Prior service cost/(credit)	(8,458)	(12,946)
Net amount recognized	$ 9,025	$ 7,790