Pension Plans and Other Postretirement Benefits - Domestic and Foreign Pension and Postretirement Defined Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Total net pension and postretirement benefits (credit) cost	$ (1,663)	$ 586	$ (4,975)	$ 1,641
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,202	1,118	3,623	3,371
Interest cost	6,696	8,314	20,049	24,854
Expected return on assets	(10,065)	(9,414)	(30,156)	(28,311)
Amortization of prior service benefit	9	(5)	27	7
Total net pension and postretirement benefits (credit) cost	(2,158)	13	(6,457)	(79)
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	27	24	79	73
Interest cost	468	549	1,403	1,647
Total net pension and postretirement benefits (credit) cost	$ 495	$ 573	$ 1,482	$ 1,720