Consolidated Condensed Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net earnings	$ 45,316	$ 36,886
Other comprehensive income:
Changes in currency translation adjustment and other	15,762	11,765
Amortization of pension and postretirement items	7,468	7,215
Income tax expense related to amortization of pension and postretirement items	(2,014)	(1,609)
Amortization of pension and postretirement items, net of tax	5,454	5,606
Other comprehensive income, net of taxes	21,216	17,371
Comprehensive income	$ 66,532	$ 54,257