CONSOLIDATED CONDENSED STATEMENTS OF EARNINGS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
CONSOLIDATED CONDENSED STATEMENTS OF EARNINGS (Unaudited) [Abstract]
Revenue	$ 363,041	$ 338,475	$ 719,518	$ 679,872
Cost of products sold	241,571	219,250	474,977	439,702
Selling and administrative expenses	69,289	74,845	136,679	171,753
Operating income	52,181	44,380	107,862	68,417
Interest expense	5,555	4,717	11,110	9,528
Earnings before income taxes	46,626	39,663	96,752	58,889
Income taxes	7,503	8,889	19,435	14,923
Net earnings	$ 39,123	$ 30,774	$ 77,317	$ 43,966
Weighted average number of shares outstanding:
Basic (in shares)	42,281	44,023	42,578	44,112
Diluted (in shares)	42,371	44,290	42,701	44,384
Earnings per common share:
Basic (in dollars per share)	$ 0.93	$ 0.70	$ 1.82	$ 1.00
Diluted (in dollars per share)	0.92	0.69	1.81	0.99
Dividends declared per common share (in dollars per share)	$ 0.33	$ 0.30	$ 0.66	$ 0.60