XML 52 R40.htm IDEA: XBRL DOCUMENT v3.7.0.1
Fair Value of Derivative Designated as Cash Flow Hedge Instrument (Detail) - USD ($)
$ in Thousands
Jul. 31, 2017
Apr. 30, 2017
Designated as Hedge Instrument | Interest Rate Swap    
Derivative liability:    
Interest rate swap contract $ 1,050 $ 947