Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Revenue:
Product	$ 198,749	$ 168,141	$ 159,948
Service	151,801	140,538	130,592
Total revenue	350,550	308,679	290,540
Cost of revenue:
Product	45,752	39,271	38,175
Service	28,256	26,401	23,186
Total cost of revenue	74,008	65,672	61,361
Gross profit	276,542	243,007	229,179
Operating expenses:
Research and development	61,546	49,478	40,628
Sales and marketing	116,807	109,624	105,271
General and administrative	29,718	27,488	23,308
Amortization of acquired intangible assets	2,877	2,131	1,907
Restructuring charges	1,065	603	0
Total operating expenses	212,013	189,324	171,114
Income from operations	64,529	53,683	58,065
Interest and other expense, net:
Interest income	508	419	672
Interest expense	(1,291)	(1,766)	(2,452)
Other (income) expense, net	(10)	(728)	8
Loss on extinguishment of debt	0	(690)	0
Total interest and other expense, net	(793)	(2,765)	(1,772)
Income before income tax expense	63,736	50,918	56,293
Income tax expense	23,127	18,490	19,028
Net income	$ 40,609	$ 32,428	$ 37,265
Basic net income per share	$ 0.97	$ 0.77	$ 0.89
Diluted net income per share	$ 0.96	$ 0.76	$ 0.87
Weighted average common shares outstanding used in computing:
Net income per share-basic	41,665	42,035	42,059
Net income per share-diluted	42,322	42,750	42,973