Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013
Revenue:
Product	$ 76,446	$ 68,561	$ 198,765	$ 163,895
Service	46,387	41,867	135,519	120,435
Total revenue	122,833	110,428	334,284	284,330
Cost of revenue:
Product	18,310	14,534	45,015	36,117
Service	8,672	9,068	26,158	24,111
Total cost of revenue	26,982	23,602	71,173	60,228
Gross profit	95,851	86,826	263,111	224,102
Operating expenses:
Research and development	18,864	18,348	56,872	50,951
Sales and marketing	34,836	32,425	104,304	96,184
General and administrative	13,391	7,929	33,211	22,367
Amortization of acquired intangible assets	821	860	2,539	2,571
Total operating expenses	67,912	59,562	196,926	172,073
Income from operations	27,939	27,264	66,185	52,029
Interest and other income (expense), net:
Interest income	95	66	298	210
Interest expense	(191)	(198)	(580)	(575)
Other (expense) income, net	(416)	176	(904)	277
Total interest and other income (expense), net	(512)	44	(1,186)	(88)
Income before income tax expense	27,427	27,308	64,999	51,941
Income tax expense	9,798	10,014	24,661	19,511
Net income	$ 17,629	$ 17,294	$ 40,338	$ 32,430
Basic net income per share (in USD per share)	$ 0.43	$ 0.42	$ 0.98	$ 0.78
Diluted net income per share (in USD per share)	$ 0.42	$ 0.41	$ 0.97	$ 0.77
Weighted average common shares outstanding used in computing:
Net income per share - basic (in shares)	41,206	41,425	41,128	41,417
Net income per share - diluted (in shares)	41,536	41,884	41,679	41,969