Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2015	Oct. 31, 2014
Income Statement [Abstract]
Revenue	$ 49,926	$ 47,325	$ 98,802	$ 93,302
Cost of revenue	19,146	17,414	38,694	33,770
Gross profit	30,780	29,911	60,108	59,532
Operating expenses:
Sales and marketing	16,502	18,931	35,668	39,926
Research and development	10,354	9,306	20,887	19,036
General and administrative	7,643	8,100	15,881	15,993
Acquisition-related and other	224	2,326	926	2,818
Amortization of acquired intangible assets	310	310	619	619
Total operating expenses	35,033	38,973	73,981	78,392
Operating loss	(4,253)	(9,062)	(13,873)	(18,860)
Other income (expense), net:
Interest income	74	10	151	16
Interest expense	(461)	(250)	(1,032)	(482)
Other expense	(88)	(348)	(306)	(620)
Total other expense, net	(475)	(588)	(1,187)	(1,086)
Loss from continuing operations before income taxes	(4,728)	(9,650)	(15,060)	(19,946)
Income tax expense	124	258	36	270
Net loss from continuing operations	(4,852)	(9,908)	(15,096)	(20,216)
Loss from discontinued operations, net of tax	0	0	0	(1,257)
Net loss applicable to common stockholders	$ (4,852)	$ (9,908)	$ (15,096)	$ (21,473)
Net loss per share applicable to common stockholders:
Continuing operations	$ (0.06)	$ (0.13)	$ (0.19)	$ (0.26)
Discontinued operations	0.00	0.00	0.00	(0.02)
Basic and diluted loss per share:	$ (0.06)	$ (0.13)	$ (0.19)	$ (0.28)
Basic and diluted weighted average number of shares outstanding	80,678	78,280	80,426	78,023