XML 63 R51.htm IDEA: XBRL DOCUMENT v3.10.0.1
Accounts Receivable - Allowance for Doubtful Accounts (Detail) - Allowance for doubtful accounts [Member] - USD ($)
$ in Thousands
3 Months Ended
Jul. 29, 2018
Jul. 30, 2017
Valuation and Qualifying Accounts Disclosure [Line Items]    
Beginning balance $ (357) $ (414)
Provision for bad debts (9) 89
Net write-offs, net of recoveries 0 0
Ending balance $ (366) $ (325)