Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Revenue:
Product	$ 52,676	$ 46,005	$ 139,100	$ 113,616
Service	38,891	37,292	113,373	105,601
Total revenue	91,567	83,297	252,473	219,217
Cost of revenue:
Product	12,182	10,731	32,582	27,439
Service	6,982	6,508	20,386	19,273
Total cost of revenue	19,164	17,239	52,968	46,712
Gross profit	72,403	66,058	199,505	172,505
Operating expenses:
Research and development	15,352	13,593	44,630	36,073
Sales and marketing	30,105	27,518	86,997	81,144
General and administrative	8,539	6,564	22,071	20,135
Amortization of acquired intangible assets	846	565	2,077	1,541
Restructuring charges	(1)	372	1,065	372
Total operating expenses	54,841	48,612	156,840	139,265
Income from operations	17,562	17,446	42,665	33,240
Interest and other expense, net:
Interest income	115	104	423	304
Interest expense	(293)	(472)	(1,085)	(1,449)
Other income (expense), net	74	(150)	86	(607)
Loss on extinguishment of debt	0	(690)	0	(690)
Total interest and other expense, net	(104)	(1,208)	(576)	(2,442)
Income before income tax expense	17,458	16,238	42,089	30,798
Income tax expense	6,320	6,207	16,033	11,317
Net income	$ 11,138	$ 10,031	$ 26,056	$ 19,481
Basic net income per share	$ 0.27	$ 0.24	$ 0.62	$ 0.46
Diluted net income per share	$ 0.26	$ 0.24	$ 0.62	$ 0.46
Weighted average common shares outstanding used in computing:
Net income per share - basic	41,709	41,523	41,715	42,126
Net income per share - diluted	42,298	42,303	42,364	42,815