Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014
Income Statement [Abstract]
Revenue	$ 199,766	$ 191,181	$ 168,145
Cost of revenue	76,867	69,906	52,905
Gross profit	122,899	121,275	115,240
Operating expenses:
Sales and marketing	69,808	78,373	86,482
Research and development	41,477	37,695	37,585
General and administrative	30,398	30,507	26,370
Acquisition-related and other	1,415	4,046	16,184
Restructuring charges	1,575	0	0
Amortization of acquired intangible assets	1,237	1,237	1,135
Total operating expenses	145,910	151,858	167,756
Operating loss	(23,011)	(30,583)	(52,516)
Other income (expense), net:
Interest income	412	95	143
Interest expense	(2,180)	(1,451)	(190)
Other expense	(522)	(1,171)	(783)
Total other expense, net	(2,290)	(2,527)	(830)
Loss from continuing operations before income taxes	(25,301)	(33,110)	(53,346)
Income tax expense (benefit)	38	54	(500)
Net loss from continuing operations	(25,339)	(33,164)	(52,846)
Loss from discontinued operations, net of tax	0	(1,257)	(10,320)
Net loss applicable to common stockholders	$ (25,339)	$ (34,421)	$ (63,166)
Net loss per share applicable to common stockholders:
Continuing operations	$ (0.31)	$ (0.42)	$ (0.70)
Discontinued operations	0.00	(0.02)	(0.14)
Basic and diluted loss per share:	$ (0.31)	$ (0.44)	$ (0.84)
Basic and diluted weighted average number of shares outstanding	80,859	78,645	75,564