CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenue	$ 1,046,487	$ 990,533	$ 996,810
Cost of revenue (exclusive of depreciation, shown separately below)	543,211	535,597	525,122
Other operating expenses:
Research and development	134,691	122,847	127,994
Selling, general and administrative	214,694	198,279	191,329
Depreciation	24,835	22,926	21,422
Restructuring and reorganization charges	4,870	5,328	4,834
Total operating expenses	922,301	884,977	870,701
Operating income	124,186	105,556	126,109
Other income (expense):
Interest expense	(14,569)	(15,500)	(17,748)
Amortization of original issue discount	(3,021)	(2,983)	(2,819)
Interest and investment income, net	365	1,244	1,785
Other, net	(6,015)	(2,961)	(1,604)
Total other	(23,240)	(20,200)	(20,386)
Income before income taxes	100,946	85,356	105,723
Income tax provision	(28,615)	(26,645)	(22,953)
Net income	$ 72,331	$ 58,711	$ 82,770
Weighted-average shares outstanding:
Basic	31,776	32,010	32,051
Diluted	32,010	32,278	32,465
Earnings per common share:
Basic	$ 2.28	$ 1.83	$ 2.58
Diluted	$ 2.26	$ 1.82	$ 2.55