CONDENSED CONSOLIDATED STATEMENTS OF EARNINGS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net sales
Net sales	$ 578,314	$ 547,522
Total net sales	578,314	547,522
Cost of sales
Total cost of sales	381,441	366,331
Gross profit	196,873	181,191
Research and development expenses	17,241	15,941
Selling expenses	31,477	31,520
General and administrative expenses	76,110	69,232
Operating income	72,045	64,498
Interest expense	(7,272)	(8,204)
Other income, net	5,478	4,683
Earnings before income taxes	70,251	60,977
Provision for income taxes	(14,658)	(17,334)
Net earnings	$ 55,593	$ 43,643
Earnings Per Share, Basic [Abstract]
Basic earnings per share (usd per share)	$ 1.30	$ 0.99
Earnings Per Share, Diluted [Abstract]
Diluted earnings per share (usd per share)	1.29	0.98
Dividends per share	$ 0.15	$ 0.15
Weighted average shares outstanding:
Basic (shares)	42,799	44,188
Diluted (shares)	43,058	44,678
Product [Member]
Net sales
Net sales	$ 471,599	$ 444,687
Cost of sales
Cost of product sales	311,956	299,311
Service [Member]
Net sales
Net sales	106,715	102,835
Cost of sales
Cost of product sales	$ 69,485	$ 67,020