CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Total revenue	$ 1,681,297	$ 1,515,892	$ 1,293,636
Cost of sales:
Amortization	40,642	21,710	27,034
Total cost of sales	225,264	166,273	155,885
Gross profit	1,456,033	1,349,619	1,137,751
Operating expenses:
Selling, general and administrative	587,707	521,200	413,580
Research and development	355,371	298,210	233,802
Amortization	16,599	15,169	13,795
Total operating expenses	959,677	834,579	661,177
Operating income	496,356	515,040	476,574
Interest income	5,073	12,796	11,419
Interest expense	(10,988)	(3,461)	(59)
Other income (expense), net	3,484	(1,792)	(849)
Income before income tax provision	493,925	522,583	487,085
Income tax provision	60,038	71,288	67,710
Net income	$ 433,887	$ 451,295	$ 419,375
Earnings per share – basic:
Earnings per share	$ 5.05	$ 5.36	$ 4.99
Weighted average shares	85,840	84,259	83,973
Earnings per share – diluted:
Earnings per share	$ 4.97	$ 5.25	$ 4.88
Weighted average shares	87,288	85,925	85,913
Software licenses
Revenue:
Total revenue	$ 780,850	$ 699,630	$ 576,717
Cost of sales:
Total cost of sales	30,618	23,944	18,619
Maintenance and service
Revenue:
Total revenue	900,447	816,262	716,919
Cost of sales:
Total cost of sales	$ 154,004	$ 120,619	$ 110,232