CONSOLIDATED CONDENSED STATEMENTS OF EARNINGS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
CONSOLIDATED CONDENSED STATEMENTS OF EARNINGS (Unaudited) [Abstract]
Revenue	$ 339,186	$ 363,041	$ 686,699	$ 719,518
Cost of products sold	227,418	241,571	459,706	474,977
Selling and administrative expenses	64,400	69,289	130,205	136,679
Operating income	47,368	52,181	96,788	107,862
Interest expense	5,200	5,555	10,602	11,110
Earnings before income taxes	42,168	46,626	86,186	96,752
Income taxes	7,837	7,503	19,048	19,435
Net earnings	$ 34,331	$ 39,123	$ 67,138	$ 77,317
Weighted average number of shares outstanding:
Basic (in shares)	42,270	42,281	42,255	42,578
Diluted (in shares)	42,300	42,371	42,287	42,701
Earnings per common share:
Basic (in dollars per share)	$ 0.81	$ 0.93	$ 1.59	$ 1.82
Diluted (in dollars per share)	0.81	0.92	1.59	1.81
Dividends declared per common share (in dollars per share)	$ 0.36	$ 0.33	$ 0.72	$ 0.66