Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues	$ 1,158,538	$ 1,023,586	$ 859,773
Costs and operating expenses:
Cost of revenues	374,543	303,403	249,938
Research and development	52,333	54,766	43,658
Sales and marketing	227,331	226,704	179,421
General and administrative	191,726	167,779	146,100
Amortization of other intangible assets	17,070	16,657	16,722
Restructuring charge	4,886	0	454
Total costs and operating expenses	867,889	769,309	636,293
Income from operations	290,649	254,277	223,480
Interest income	10,670	12,163	15,643
Interest expense	0	1,697	2,839
Other income (expense), net	(6,125)	2,468	(163)
(Loss) gain on investments, net	(249)	396	785
Loss on early extinguishment of debt	0	(299)	0
Income before provision for income taxes	307,195	262,372	237,232
Provision for income taxes	106,291	91,152	91,319
Net income	$ 200,904	$ 171,220	$ 145,913
Net income per weighted average share:
Basic	$ 1.09	$ 0.97	$ 0.85
Diluted	$ 1.07	$ 0.90	$ 0.78
Shares used in per share calculations:
Basic	183,866	177,309	171,425
Diluted	187,556	190,650	188,658