Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Jul. 31, 2017	Jul. 31, 2016
Income Statement [Abstract]
Revenue	$ 52,158	$ 50,093
Cost of revenue	19,765	18,756
Gross profit	32,393	31,337
Operating expenses:
Sales and marketing	14,604	15,304
Research and development	10,503	11,073
General and administrative	8,585	8,259
Restructuring charges	40	327
Acquisition-related and other	261	176
Amortization of acquired intangible assets	309	309
Total operating expenses	34,302	35,448
Operating loss	(1,909)	(4,111)
Other income (expense), net:
Interest income	86	142
Interest expense	(394)	(489)
Other income (expense)	25	(512)
Total other expense, net	(283)	(859)
Loss before income taxes	(2,192)	(4,970)
Income tax expense	124	135
Net loss	$ (2,316)	$ (5,105)
Net loss per share:
Basic and diluted loss per share	$ (0.03)	$ (0.06)
Basic and diluted weighted average number of shares outstanding	84,663	82,214