Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Revenue:
Product	$ 168,141	$ 159,948	$ 142,113
Service	140,538	130,592	118,229
Total revenue	308,679	290,540	260,342
Cost of revenue:
Product	39,271	38,175	35,564
Service	26,401	23,186	20,500
Total cost of revenue	65,672	61,361	56,064
Gross profit	243,007	229,179	204,278
Operating expenses:
Research and development	49,478	40,628	36,650
Sales and marketing	109,624	105,271	99,059
General and administrative	27,488	23,308	20,609
Amortization of acquired intangible assets	2,131	1,907	2,057
Restructuring charges	603	0	0
Total operating expenses	189,324	171,114	158,375
Income from operations	53,683	58,065	45,903
Interest and other expense, net:
Interest income	419	672	644
Interest expense	(1,766)	(2,452)	(3,464)
Other (income) expense, net	(728)	8	(12)
Loss on extinguishment of debt	(690)	0	0
Total interest and other expense, net	(2,765)	(1,772)	(2,832)
Income before income tax expense	50,918	56,293	43,071
Income tax expense	18,490	19,028	15,154
Net income	$ 32,428	$ 37,265	$ 27,917
Basic net income per share	$ 0.77	$ 0.89	$ 0.69
Diluted net income per share	$ 0.76	$ 0.87	$ 0.67
Weighted average common shares outstanding used in computing:
Net income per share-basic	42,035	42,059	40,691
Net income per share-diluted	42,750	42,973	41,915