CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue:
Software licenses	$ 501,870	$ 425,881	$ 351,033
Maintenance and service	296,148	265,568	229,203
Total revenue	798,018	691,449	580,236
Cost of sales:
Software licenses	24,512	15,884	10,770
Amortization	40,889	33,728	32,757
Maintenance and service	74,115	69,402	57,352
Total cost of sales	139,516	119,014	100,879
Gross profit	658,502	572,435	479,357
Operating expenses:
Selling, general and administrative	205,178	180,357	155,096
Research and development	132,628	108,530	88,990
Amortization	26,443	17,989	16,003
Total operating expenses	364,249	306,876	260,089
Operating income	294,253	265,559	219,268
Interest expense	(2,661)	(3,332)	(4,488)
Interest income	3,360	3,000	1,911
Other expense, net	(1,405)	(369)	(297)
Income before income tax provision	293,547	264,858	216,394
Income tax provision	90,064	84,183	63,262
Net income	$ 203,483	$ 180,675	$ 153,132
Earnings per share – basic:
Basic earnings per share (in USD per share)	$ 2.20	$ 1.96	$ 1.69
Weighted average shares - basic	92,622	92,120	90,684
Earnings per share – diluted:
Diluted earnings per share (in USD per share)	$ 2.14	$ 1.91	$ 1.64
Weighted average shares - diluted	94,954	94,381	93,209