Pension Plans and Other Postretirement Benefits - Pension and Postretirement Plan Contributions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Cost of goods sold	$ 516,650	$ 467,107
Selling, general and administrative expense	101,370	108,928
Other (expenses) income, net	(30,476)	265
Pension contributions	3,100	2,400
Other postretirement benefits payments	$ 500	500
Accounting Standards Update 2017-07 [Member]
Defined Benefit Plan Disclosure [Line Items]
Cost of goods sold		200
Selling, general and administrative expense		900
Other (expenses) income, net		$ 1,100