CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue:
Software licenses	$ 568,174	$ 555,105	$ 564,502
Maintenance and service	420,291	387,648	371,519
Total revenue	988,465	942,753	936,021
Cost of sales:
Software licenses	28,860	29,105	30,607
Amortization	38,092	38,755	37,653
Maintenance and service	79,908	79,386	85,126
Total cost of sales	146,860	147,246	153,386
Gross profit	841,605	795,507	782,635
Operating expenses:
Selling, general and administrative	269,515	253,603	246,376
Research and development	183,093	168,831	165,421
Amortization	12,755	19,394	23,388
Total operating expenses	465,363	441,828	435,185
Operating income	376,242	353,679	347,450
Interest expense	(221)	(325)	(779)
Interest income	4,209	2,829	3,002
Other income (expense), net	85	582	(1,534)
Income before income tax provision	380,315	356,765	348,139
Income tax provision	114,679	104,244	93,449
Net income	$ 265,636	$ 252,521	$ 254,690
Earnings per share – basic:
Earnings per share	$ 3.05	$ 2.82	$ 2.77
Weighted average shares	87,227	89,561	92,067
Earnings per share – diluted:
Earnings per share	$ 2.99	$ 2.76	$ 2.70
Weighted average shares	88,969	91,502	94,194