Geographic And Segment Reporting (Schedule Of Business Segment Information) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Licenses	$ 87,968	$ 80,582	$ 232,334	$ 222,663
Services	132,432	112,460	379,193	327,652
Total revenues	220,400	193,042	611,527	550,315
Cost of licenses	2,674	2,465	7,008	6,178
Cost of services	22,449	16,907	66,049	47,267
Amortization of purchased technology	6,291	4,105	16,190	12,564
Total cost of revenues	31,414	23,477	89,247	66,009
Gross profit	188,986	169,565	522,280	484,306
Licenses [Member]
Licenses	87,968	80,582	232,334	222,663
Cost of licenses	8,965	6,570	23,198	18,742
Gross profit	79,003	74,012	209,136	203,921
Maintenance Services [Member]
Maintenance Services	117,131	100,731	335,474	295,019
Cost of services	10,605	7,985	31,086	22,622
Gross profit	106,526	92,746	304,388	272,397
Professional Services [Member]
Professional Services	15,301	11,729	43,719	32,633
Cost of services	11,844	8,922	34,963	24,645
Gross profit	$ 3,457	$ 2,807	$ 8,756	$ 7,988