CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Revenue	$ 452,707	$ 434,124	$ 892,325	$ 840,938
Cost of goods sold	220,156	227,392	441,860	442,885
Gross profit	232,551	206,732	450,465	398,053
Operating expenses:
Research and development	46,429	43,046	90,990	85,029
Selling, general and administrative	97,456	97,056	205,139	187,308
Loss on sale of business	0	0	10,178	0
Total operating expenses	143,885	140,102	306,307	272,337
Earnings from operations	88,666	66,630	144,158	125,716
Interest expense	3,992	4,472	8,044	8,925
Interest income	(656)	(355)	(1,612)	(626)
Other income, net	2,377	(1,027)	158	(1,687)
Earnings before income taxes	82,953	63,540	137,568	119,104
Income tax provision	11,390	12,127	26,810	25,120
Net earnings	$ 71,563	$ 51,413	$ 110,758	$ 93,984
Net earnings per share:
Basic earnings per share (in dollars per share)	$ 0.52	$ 0.38	$ 0.80	$ 0.69
Diluted earnings per share (in dollars per share)	$ 0.51	$ 0.37	$ 0.79	$ 0.68
Weighted Average Number of Shares Outstanding, Basic	137,749	136,865	138,124	136,613
Weighted Average Number of Shares Outstanding, Diluted	140,149	138,449	140,564	138,266