CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Revenue	$ 405,228	$ 381,928	$ 1,187,429	$ 1,119,420
Cost of goods sold	213,852	201,189	635,041	573,169
Gross profit	191,376	180,739	552,388	546,251
Operating expenses:
Research and development	32,664	31,200	106,020	101,100
Selling, general and administrative	77,863	73,557	242,930	232,884
Total operating expenses	110,527	104,757	348,950	333,984
Earnings from operations	80,849	75,982	203,438	212,267
Interest expense	5,736	3,670	13,543	10,689
Interest income	(336)	(319)	(924)	(861)
Other expense, net	241	1,455	138	1,775
Earnings before income taxes	75,208	71,176	190,681	200,664
Income tax provision (benefit)	16,575	(1,896)	85,555	29,182
Net earnings	$ 58,633	$ 73,072	$ 105,126	$ 171,482
Earnings per share:
Basic	$ 0.43	$ 0.52	$ 0.76	$ 1.23
Diluted	$ 0.43	$ 0.52	$ 0.76	$ 1.21
Weighted average shares outstanding:
Basic	136,963	139,596	137,438	139,808
Diluted	137,938	140,525	138,594	141,262