Cash dividend and declared dividends (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
Jan. 31, 2020	Jan. 31, 2019
Cash dividend and declared dividends
Dividends paid, per share	$ 0.02	$ 0.02
Dividends paid	$ 193	$ 186

Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585

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