Dividends - Disclosure of Detailed Information About Dividends Explanatory (Details) - NZD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Australian Franking Credits [Member]
DisclosureOfDividendsLineItems [Line Items]
Unused tax credits for which no deferred tax asset recognised	$ 3,995	$ 3,995	$ 3,757
New Zealand Imputation Credits [Member]
DisclosureOfDividendsLineItems [Line Items]
Unused tax credits for which no deferred tax asset recognised	$ 236	$ 236	$ 235

The amount of unused tax credits for which no deferred tax asset is recognised in the statement of financial position. [Refer: Unused tax credits [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 12
-IssueDate 2018-01-01
-Paragraph 81
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=12&date=2018-03-01&anchor=para_81_e&doctype=Standard
-URIDate 2018-03-16

Name:	ifrs-full_UnusedTaxCreditsForWhichNoDeferredTaxAssetRecognised
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant