Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues
Total revenues	$ 737,671	$ 566,336	$ 433,047
Cost of revenues
Operating expenses	89,336	76,231	62,438
Depreciation and amortization	20,411	14,532	9,590
Total cost of revenues	109,747	90,763	72,028
Administrative expenses
Sales and marketing	179,286	143,881	110,846
Research and development	73,080	46,247	30,430
General and administrative	127,534	96,605	80,228
Depreciation and amortization	21,800	15,125	9,805
Total administrative expenses	401,700	301,858	231,309
Total operating expenses	511,447	392,621	303,337
Operating income	226,224	173,715	129,710
Interest expense	(940)	(766)	(911)
Other income (expense), net	803	1,762	(1,067)
Income before income taxes	226,087	174,711	127,732
Provision for income taxes	45,511	37,646	4,246
Net income	$ 180,576	$ 137,065	$ 123,486
Earnings per share, basic	$ 3.14	$ 2.37	$ 2.13
Earnings per share, diluted	$ 3.09	$ 2.34	$ 2.10
Weighted average shares outstanding:
Basic	57,561	57,711	57,839
Diluted	58,395	58,582	58,790
Recurring [Member]
Revenues
Total revenues	$ 724,428	$ 557,255	$ 425,424
Implementation and Other [Member]
Revenues
Total revenues	$ 13,243	$ 9,081	$ 7,623