CONSOLIDATED CONDENSED STATEMENTS OF EARNINGS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
CONSOLIDATED CONDENSED STATEMENTS OF EARNINGS (Unaudited) [Abstract]
Revenue	$ 323,566	$ 317,650	$ 997,333	$ 1,004,349
Cost of products sold	217,920	215,250	677,580	674,956
Selling and administrative expenses	64,491	63,612	201,912	193,817
Operating income	41,155	38,788	117,841	135,576
Interest expense	3,497	4,936	11,412	15,538
Earnings before income taxes	37,658	33,852	106,429	120,038
Income taxes	4,748	1,981	22,126	21,029
Net earnings	$ 32,910	$ 31,871	$ 84,303	$ 99,009
Weighted average number of common shares outstanding:
Basic (in shares)	42,307	42,272	42,299	42,261
Diluted (in shares)	42,349	42,299	42,326	42,291
Earnings per common share:
Basic (in dollars per share)	$ 0.78	$ 0.75	$ 1.99	$ 2.34
Diluted (in dollars per share)	0.78	0.75	1.99	2.34
Dividends declared per common share (in dollars per share)	$ 0.39	$ 0.36	$ 1.17	$ 1.08