Pension Plans and Other Postretirement Benefits Components of Pension and Postretirement Benefits Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Weighted-average assumption percentages:
Expected return on plan assets	6.72%	6.73%	6.73%
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 98	$ 117	$ 121
Interest cost	2,197	2,168	2,340
Expected return on assets	0	(7)	(110)
Actuarial loss (gain)	5,449	(5,400)	2,014
Amortization of prior service benefit	0	(48)	(95)
Total net pension benefits cost (credit)	$ 7,744	$ (3,170)	$ 4,270
Weighted-average assumption percentages:
Discount rate	4.55%	3.99%	4.35%
Expected return on plan assets	0.00%	7.00%	7.00%
Rate of compensation increase	3.50%	3.50%	3.50%
U.S. Plans | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 730	$ 1,043	$ 985
Interest cost	28,199	26,804	28,614
Expected return on assets	(33,926)	(38,621)	(36,243)
Actuarial loss (gain)	7,106	30,234	(13,910)
Amortization of prior service benefit	0	60	75
Total net pension benefits cost (credit)	$ 2,109	$ 19,520	$ (20,479)
Weighted-average assumption percentages:
Expected return on plan assets	6.89%	6.89%	6.89%
Rate of compensation increase	0.00%	0.00%	0.00%
Foreign Plans | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3,680	$ 3,919	$ 2,547
Interest cost	4,998	5,144	5,128
Expected return on assets	(3,837)	(4,204)	(4,441)
Actuarial loss (gain)	16,784	(10,833)	483
Amortization of prior service benefit	37	34	56
Total net pension benefits cost (credit)	$ 21,662	$ (5,940)	$ 3,773
Weighted-average assumption percentages:
Expected return on plan assets	5.51%	5.52%	6.16%
Rate of compensation increase	3.63%	3.18%	3.18%