Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net earnings (loss)	$ (74,099)	$ 75,215	$ (183,712)	$ 120,531
Other comprehensive income (loss):
Changes in currency translation adjustment and other	7,878	(7,763)	(76,742)	7,999
Amortization of pension and postretirement items	7,371	7,377	15,150	14,845
Income tax expense related to amortization of pension and postretirement items	(1,492)	(1,381)	(3,105)	(3,395)
Amortization of pension and postretirement items, net of tax	5,879	5,996	12,045	11,450
Change in net actuarial loss and prior service cost	(4,539)	(9,440)	(4,539)	(9,440)
Income tax benefit related to change in net actuarial loss and prior service cost	1,087	2,237	1,087	2,237
Change in net actuarial loss and prior service cost, net of taxes	(3,452)	(7,203)	(3,452)	(7,203)
Other comprehensive income (loss), net of taxes	10,305	(8,970)	(68,149)	12,246
Comprehensive income	$ (63,794)	$ 66,245	$ (251,861)	$ 132,777