XML 63 R45.htm IDEA: XBRL DOCUMENT v3.7.0.1
Summary of Short-Term Investments by Geographic Area (Detail) - USD ($)
$ in Thousands
Apr. 30, 2017
May 01, 2016
Schedule of Investments [Line Items]    
short-term investments $ 2,443 $ 4,359
Canada [Member]    
Schedule of Investments [Line Items]    
short-term investments 1,362 3,294
United States [Member]    
Schedule of Investments [Line Items]    
short-term investments $ 1,081 $ 1,065