CONSOLIDATED CONDENSED STATEMENTS OF EARNINGS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
CONSOLIDATED CONDENSED STATEMENTS OF EARNINGS (Unaudited) [Abstract]
Revenue	$ 317,650	$ 342,734	$ 1,004,349	$ 1,062,252
Cost of products sold	215,250	227,161	674,956	702,138
Selling and administrative expenses	63,612	65,309	193,817	201,988
Operating income	38,788	50,264	135,576	158,126
Interest expense	4,936	5,407	15,538	16,517
Earnings before income taxes	33,852	44,857	120,038	141,609
Income taxes (benefit)	1,981	(2,336)	21,029	17,099
Net earnings	$ 31,871	$ 47,193	$ 99,009	$ 124,510
Weighted average number of shares outstanding:
Basic (in shares)	42,272	42,240	42,261	42,464
Diluted (in shares)	42,299	42,313	42,291	42,571
Earnings per common share:
Basic (in dollars per share)	$ 0.75	$ 1.12	$ 2.34	$ 2.93
Diluted (in dollars per share)	0.75	1.12	2.34	2.92
Dividends declared per common share (in dollars per share)	$ 0.36	$ 0.33	$ 1.08	$ 0.99