Consolidated statements of operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Total revenue	$ 106,773	$ 93,360	$ 234,632	$ 206,617
Total cost of revenue	31,023	29,456	63,908	58,498
Gross profit	75,750	63,904	170,724	148,119
Operating expenses:
Research and development	29,829	24,744	57,345	47,447
Sales and marketing	26,221	19,979	52,672	38,606
General and administrative	19,851	17,412	40,180	34,402
Amortization of intangible assets	3,600	1,986	7,128	3,926
Other operating income	(549)	(392)	(1,166)	(2,583)
Total operating expenses	78,952	63,729	156,159	121,798
Operating (loss) income	(3,202)	175	14,565	26,321
Interest expense	590	45	860	61
Other income, net	(505)	(176)	(115)	(1,076)
(Loss) income before income taxes	(3,287)	306	13,820	27,336
Income tax (benefit) expense	(167)	1,386	3,921	3,732
Net (loss) income	$ (3,120)	$ (1,080)	$ 9,899	$ 23,604
Income per share:
Net (loss) income per share attributable to common stockholders, basic	$ (0.04)	$ (0.02)	$ 0.14	$ 0.37
Net (loss) income per share attributable to common stockholders, diluted	$ (0.04)	$ (0.02)	$ 0.13	$ 0.32
Weighted average shares outstanding:
Weighted average number of shares used in computing net (loss) income per share, basic	71,373	65,580	71,081	64,614
Weighted average number of shares used in computing net (loss) income per share, diluted	71,373	65,580	77,017	72,881
License [Member]
Total revenue	$ 56,653	$ 46,700	$ 133,274	$ 113,635
Total cost of revenue	2,954	4,068	8,775	7,798
Maintenance and Other Services [Member]
Total revenue	27,755	23,907	54,425	46,641
Total cost of revenue	9,430	7,915	17,961	15,107
Total Software [Member]
Total revenue	84,408	70,607	187,699	160,276
Total cost of revenue	12,384	11,983	26,736	22,905
Software Related Services [Member]
Total revenue	7,907	8,707	17,679	18,180
Total cost of revenue	6,612	6,512	13,130	13,221
Total Software and Related Services [Member]
Total revenue	92,315	79,314	205,378	178,456
Total cost of revenue	18,996	18,495	39,866	36,126
Client Engineering Services [Member]
Total revenue	12,412	12,417	24,462	24,497
Total cost of revenue	10,033	9,960	19,833	20,160
Other [Member]
Total revenue	2,046	1,629	4,792	3,664
Total cost of revenue	$ 1,994	$ 1,001	$ 4,209	$ 2,212