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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Total net pension and postretirement benefits (credit) cost	$ (1,593)	$ 478	$ (3,312)	$ 1,055
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,207	1,123	2,421	2,253
Interest cost	6,666	8,220	13,353	16,540
Expected return on assets	(10,028)	(9,445)	(20,091)	(18,897)
Amortization of prior service benefit	69	6	18	12
Total net pension and postretirement benefits (credit) cost	(2,086)	(96)	(4,299)	(92)
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	26	25	52	49
Interest cost	467	549	935	1,098
Total net pension and postretirement benefits (credit) cost	$ 493	$ 574	$ 987	$ 1,147