Income Taxes - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Income tax [line items]
Name of subsidiary	Wheaton Precious Metals International Ltd
Proportion of ownership interest in subsidiary	100.00%
Non Capital Losses	$ 119
Temporary differences associated with investments in subsidiaries	1,000
Canada [member]
Income tax [line items]
Capital losses	3
2038 expiration [member]
Income tax [line items]
Non Capital Losses	40
2039 expiration [member]
Income tax [line items]
Non Capital Losses	63
2040 expiration [member]
Income tax [line items]
Non Capital Losses	$ 16