Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Financial Risk Management - Sensitivity Analysis for Types of Market Risk (Details)

v3.19.2
Financial Risk Management - Sensitivity Analysis for Types of Market Risk (Details) - NZD ($)
$ in Thousands
Jan. 31, 2019
Jan. 31, 2018
Jan. 31, 2017
Jun. 30, 2016
Jun. 30, 2015
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Equity $ 10,519 $ (5,710) $ (9,044) $ (17,876) $ 2,839
10% Increase [Member]          
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Risk exposure associated with instruments sharing characteristic 200 402 642    
10% Decrease [Member]          
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Risk exposure associated with instruments sharing characteristic (200) (402) (642)    
US [Member] | 10% Increase [Member]          
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Risk exposure associated with instruments sharing characteristic (954) (1,509) (1,196)    
US [Member] | 10% Decrease [Member]          
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Risk exposure associated with instruments sharing characteristic 954 1,509 1,196    
AUD [Member] | 10% Increase [Member]          
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Risk exposure associated with instruments sharing characteristic (5) (805) 86    
AUD [Member] | 10% Decrease [Member]          
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Risk exposure associated with instruments sharing characteristic 5 805 (86)    
GBP [Member] | 10% Increase [Member]          
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Risk exposure associated with instruments sharing characteristic (1) (175) 34    
GBP [Member] | 10% Decrease [Member]          
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Risk exposure associated with instruments sharing characteristic 1 175 (34)    
EUR [Member] | 10% Increase [Member]          
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Risk exposure associated with instruments sharing characteristic (32) (136) 186    
EUR [Member] | 10% Decrease [Member]          
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Risk exposure associated with instruments sharing characteristic 32 136 (186)    
HKD [Member] | 10% Increase [Member]          
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Risk exposure associated with instruments sharing characteristic (1) (14) 1    
HKD [Member] | 10% Decrease [Member]          
DisclosureOfFinancialRiskManagementLineItems [Line Items]          
Risk exposure associated with instruments sharing characteristic $ 1 $ 14 $ (1)