Consolidated Condensed Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net earnings	$ 88,751	$ 58,750	$ 164,514	$ 148,024
Other comprehensive income:
Changes in currency translation adjustment and other	6,554	27,648	(23,198)	70,991
Amortization of pension and postretirement items	7,163	7,960	20,793	23,741
Income tax expense related to amortization of pension and postretirement items	(1,897)	(2,812)	(4,771)	(8,324)
Amortization of pension and postretirement items, net of tax	5,266	5,148	16,022	15,417
Change in net actuarial loss and prior service cost	0	870	(1,211)	890
Income tax benefit related to change in net actuarial loss and prior service cost	0	(260)	308	(80)
Change in net actuarial loss and prior service cost, net of taxes	0	610	(903)	810
Other comprehensive income (loss), net of taxes	11,820	33,406	(8,079)	87,218
Comprehensive income	$ 100,571	$ 92,156	$ 156,435	$ 235,242