Pension Plans and Other Postretirement Benefits - Pension and Postretirement Plan Contributions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Cost of goods sold	$ 497,211	$ 479,210	$ 1,556,379	$ 1,411,614
Selling, general and administrative expense	100,167	106,471	325,174	331,984
Other income (expenses), net	3,793	(1,986)	(31,906)	(3,399)
Pension contributions	3,100	2,600	9,000	7,700
Other postretirement benefits payments	$ 800	700	$ 2,000	1,900
Accounting Standards Update 2017-07
Defined Benefit Plan Disclosure [Line Items]
Cost of goods sold		100		400
Selling, general and administrative expense		900		2,700
Other income (expenses), net		1,000		3,100
Selling, general and administrative expenses | Financial Improvement Plan
Defined Benefit Plan Disclosure [Line Items]
Multiemployer plan, period contributions				2,000
Other expenses, net | Financial Improvement Plan
Defined Benefit Plan Disclosure [Line Items]
Multiemployer plan, period contributions		$ 1,600		$ 4,600