Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenues	$ 70,928	$ 62,868	$ 206,391	$ 183,051
Cost of revenues	23,263	20,411	68,330	60,571
Gross profit	47,665	42,457	138,061	122,480
Operating expenses
Sales and marketing	16,937	16,952	52,404	54,023
Research and development	7,743	5,146	20,444	15,571
General and administrative	10,725	11,174	33,674	31,278
Amortization of intangible assets	1,327	928	3,897	3,086
Total operating expenses	36,732	34,200	110,419	103,958
Income from operations	10,933	8,257	27,642	18,522
Other income (expense)
Interest income, net	843	628	2,233	1,589
Other income (expense), net	(165)	(219)	28	(541)
Change in earn-out liability	22		366
Total other income, net	700	409	2,627	1,048
Income before income taxes	11,633	8,666	30,269	19,570
Income tax expense	2,692	605	5,719	2,839
Net income	8,941	8,061	24,550	16,731
Other comprehensive income (expense)
Foreign currency translation adjustments	(958)	76	73	(2,155)
Unrealized gain on investments, net of tax of $38, $41, $105, and $88, respectively	115	123	315	264
Reclassification of gain on investments into earnings, net of tax of ($48), ($11), ($109) and ($64), respectively	(145)	(33)	(326)	(191)
Total other comprehensive income (expense)	(988)	166	62	(2,082)
Comprehensive income	$ 7,953	$ 8,227	$ 24,612	$ 14,649
Net income per share
Basic	$ 0.26	$ 0.23	$ 0.70	$ 0.49
Diluted	$ 0.25	$ 0.23	$ 0.68	$ 0.48
Weighted average common shares used to compute net income per share
Basic	35,015	34,438	34,966	34,334
Diluted	35,932	35,482	35,952	35,114