Pension Plans and Other Postretirement Benefits - Domestic and Foreign Pension and Postretirement Defined Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Total net pension and postretirement benefits credit	$ (4,239)	$ (1,593)	$ (8,465)	$ (3,312)
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,172	1,207	2,351	2,421
Interest cost	5,120	6,666	10,239	13,353
Expected return on assets	(10,901)	(10,028)	(21,794)	(20,091)
Amortization of prior service benefit	29	69	58	18
Total net pension and postretirement benefits credit	(4,580)	(2,086)	(9,146)	(4,299)
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	31	26	62	52
Interest cost	310	467	619	935
Total net pension and postretirement benefits credit	$ 341	$ 493	$ 681	$ 987