Consolidated Statements of 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
Revenues
Total revenues	$ 175,006	$ 133,288	$ 544,262	$ 416,004
Cost of revenues
Operating expenses	21,088	18,158	66,153	56,403
Depreciation and amortization	5,304	3,967	14,796	10,258
Total cost of revenues	26,392	22,125	80,949	66,661
Administrative expenses
Sales and marketing	47,060	37,183	128,280	101,182
Research and development	19,605	11,526	54,869	33,507
General and administrative	25,728	22,048	98,386	73,700
Depreciation and amortization	5,665	4,161	15,848	10,652
Total administrative expenses	98,058	74,918	297,383	219,041
Total operating expenses	124,450	97,043	378,332	285,702
Operating income	50,556	36,245	165,930	130,302
Interest expense	(260)	(384)	(794)	(418)
Other income (expense), net	195	583	(168)	2,128
Income before income taxes	50,491	36,444	164,968	132,012
Provision for income taxes	11,339	7,675	29,772	26,361
Net income	$ 39,152	$ 28,769	$ 135,196	$ 105,651
Earnings per share, basic	$ 0.68	$ 0.50	$ 2.35	$ 1.83
Earnings per share, diluted	$ 0.67	$ 0.49	$ 2.31	$ 1.80
Weighted average shares outstanding:
Basic	57,654	57,727	57,528	57,785
Diluted	58,383	58,545	58,403	58,724
Recurring [Member]
Revenues
Total revenues	$ 171,405	$ 130,830	$ 534,267	$ 409,324
Implementation and Other [Member]
Revenues
Total revenues	$ 3,601	$ 2,458	$ 9,995	$ 6,680