Significant accounting policies and basis of preparation - Disclosure of detailed information about estimated useful life or depreciation rate (Details)	12 Months Ended
	Dec. 31, 2019
Motor vehicles [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives or depreciation rates, property, plant and equipment	30% declining balance
Computer equipment [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives or depreciation rates, property, plant and equipment	30% declining balance
Exploration and office equipment [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives or depreciation rates, property, plant and equipment	20% declining balance
Right of use asset - office lease [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives or depreciation rates, property, plant and equipment	4 years straight line