Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (181,544)	$ 194,609	$ 241,811
Other comprehensive income (loss), net of tax:
Foreign currency translations, net of tax of $2,374, $3,071 and $(4,992), respectively	37,252	75,319	(52,299)
Net unrealized (loss) gain on cash flow hedges, net of tax of $(583), $49 and $232, respectively	(1,748)	146	684
Net unrealized (loss) gain on available for sale securities, net of tax of $(816), $1,970 and $(1,545), respectively	(2,447)	5,910	(5,002)
Adjustments to pension and postretirement plans, net of tax of $(20,440), $(1,270) and $(13,508), respectively	(70,623)	(845)	(46,170)
Amortization of pension and postretirement costs, net of tax of $11,930, $9,497 and $21,675, respectively	38,578	28,288	64,999
Other comprehensive income (loss), net of tax	1,012	108,818	(37,788)
Comprehensive (loss) income	$ (180,532)	$ 303,427	$ 204,023