XML 86 R71.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stockholders' Equity - Summary of Stock Compensation Expense (Detail) - USD ($)
$ in Thousands
12 Months Ended
Apr. 30, 2018
Apr. 30, 2017
Apr. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock-based compensation expense $ 7,815 $ 8,590 $ 6,472
Cost of sales      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock-based compensation expense 882 1,139 564
Research and development      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock-based compensation expense 187 217 169
Selling and marketing      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock-based compensation expense 382 801 494
General and administrative      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock-based compensation expense $ 6,364 $ 6,433 $ 5,245