Other current assets - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
Apr. 30, 2016	Apr. 30, 2015
Increase (Decrease) In Other Noncurrent Assets	$ 136	$ 0

The increase (decrease) during the reporting period in other noncurrent operating assets not separately disclosed in the statement of cash flows.

No definition available.

Name:	us-gaap_IncreaseDecreaseInOtherNoncurrentAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration