Annual report pursuant to Section 13 and 15(d)

Changes in Unrecognized Tax Benefits (Detail)

v3.7.0.1
Changes in Unrecognized Tax Benefits (Detail) - USD ($)
$ in Thousands
12 Months Ended
Apr. 30, 2017
Apr. 30, 2016
Apr. 30, 2015
Income Taxes [Line Items]      
Unrecognized tax benefits, beginning of year $ 2,095 $ 2,423 $ 2,701
Settlement with tax authority   (1,963) (497)
Additions based on tax positions related to the current year 383 1,305 219
Additions based on tax positions related to prior years   330  
Unrecognized tax benefits, end of year $ 2,478 $ 2,095 $ 2,423