CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Consolidated Statements Of Operations [Abstract]
Revenue	$ 60,432	$ 66,920	$ 211,004	$ 195,017
Cost of revenue	28,978	31,775	95,393	92,548
Gross profit	31,454	35,145	115,611	102,469
Operating expenses:
Research and development	12,313	12,020	36,829	36,176
Selling, general and administrative	11,128	10,102	35,867	29,880
Amortization	384	506	1,147	1,516
Patent litigation income	0	(13,000)	0	(13,000)
Total operating expenses	23,825	9,628	73,843	54,572
Operating income	7,629	25,517	41,768	47,897
Interest income, net	(607)	(244)	(1,474)	(658)
Other expense (income), net	(132)	98	(90)	533
Income before income taxes	8,368	25,663	43,332	48,022
Provision for income taxes	1,181	8,294	6,318	14,309
Net income	$ 7,187	$ 17,369	$ 37,014	$ 33,713
Earnings per share:
Basic	$ 0.23	$ 0.55	$ 1.16	$ 1.07
Diluted	$ 0.22	$ 0.54	$ 1.14	$ 1.05
Weighted average shares outstanding:
Basic	31,901	31,571	31,807	31,455
Diluted	32,408	32,170	32,387	32,126