Consolidated Condensed Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net earnings	$ 75,215	$ 44,908	$ 120,531	$ 81,794
Other comprehensive income (loss):
Changes in currency translation adjustment and other	(7,763)	(39,998)	7,999	(28,233)
Amortization of pension and postretirement items	7,377	6,415	14,845	13,630
Income tax expense related to amortization of pension and postretirement items	(1,381)	(1,265)	(3,395)	(2,874)
Amortization of pension and postretirement items, net of tax	5,996	5,150	11,450	10,756
Change in net actuarial loss and prior service cost	(9,440)	(1,211)	(9,440)	(1,211)
Income tax benefit related to change in net actuarial loss and prior service cost	2,237	308	2,237	308
Change in net actuarial loss and prior service cost, net of taxes	(7,203)	(903)	(7,203)	(903)
Other comprehensive income (loss), net of taxes	(8,970)	(35,751)	12,246	(18,380)
Comprehensive income	$ 66,245	$ 9,157	$ 132,777	$ 63,414