Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2013
Income Statement [Abstract]
Revenue		$ 191,181	$ 168,145	$ 146,812
Cost of revenue	[1]	69,906	52,905	47,350
Gross profit		121,275	115,240	99,462
Operating expenses:
Sales and marketing	[1]	78,373	86,482	73,114
Research and development	[1]	37,695	37,585	32,169
General and administrative	[1]	30,507	26,370	30,990
Acquisition-related and other		4,046	16,184	10,487
Amortization of acquired intangible assets		1,237	1,135	549
Total operating expenses		151,858	167,756	147,309
Operating loss		(30,583)	(52,516)	(47,847)
Other income (expense), net:
Interest income		95	143	217
Interest expense		(1,451)	(190)	(526)
Other expense		(1,171)	(783)	(519)
Total other expense, net		(2,527)	(830)	(828)
Loss from continuing operations before income taxes		(33,110)	(53,346)	(48,675)
Income tax expense (benefit)		54	(500)	(1,172)
Net loss from continuing operations		(33,164)	(52,846)	(47,503)
Loss from discontinued operations, net of tax		(1,257)	(10,320)	(16,249)
Net loss applicable to common stockholders		$ (34,421)	$ (63,166)	$ (63,752)
Net loss per share applicable to common stockholders:
Continuing operations		$ (0.42)	$ (0.70)	$ (0.69)
Discontinued operations		(0.02)	(0.14)	(0.23)
Basic and diluted loss per share:		$ (0.44)	$ (0.84)	$ (0.92)
Basic and diluted weighted average number of shares outstanding		78,645	75,564	69,336

[1] Includes stock-based expense as follows: Cost of revenue $ 1,517 $ 1,155 $ 677 Sales and marketing 3,923 4,496 3,033 Research and development 2,561 2,817 2,840 General and administrative 4,677 5,357 4,608