Condensed Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2014	Jan. 31, 2013
Revenue	$ 47,997	$ 42,678	$ 138,106	$ 116,966
Cost of revenue	15,607	14,659	44,381	42,055
Gross profit	32,390	28,019	93,725	74,911
Operating expenses:
Sales and marketing	21,035	20,193	63,066	53,057
Research and development	9,312	9,217	28,452	25,153
General and administrative	7,963	8,555	20,851	31,385
Acquisition-related and other	31	2,021	15,818	4,771
Amortization of acquired intangible assets	1,304	1,165	3,913	2,543
Total operating expenses	39,645	41,151	132,100	116,909
Operating loss	(7,255)	(13,132)	(38,375)	(41,998)
Other income (expense), net:
Interest income	24	61	136	110
Other expense	(292)	(49)	(646)	(451)
Total other income (expense), net	(268)	12	(510)	(341)
Loss before income taxes	(7,523)	(13,120)	(38,885)	(42,339)
Income tax expense (benefit)	440	(2,293)	600	(1,731)
Net loss	$ (7,963)	$ (10,827)	$ (39,485)	$ (40,608)
Net loss per share:
Basic and diluted	$ (0.10)	$ (0.15)	$ (0.53)	$ (0.60)
Basic and diluted weighted average number of shares outstanding	76,071	71,940	75,047	68,115