Property, plant, equipment and development costs - Estimates prices for the current and long-term periods (Details)	Dec. 31, 2025 $ / t $ / oz	Dec. 31, 2024 $ / t $ / oz
Less than 1 year \| Gold per ounce [Member]
Property, plant, equipment and development costs
Commodity price estimates	3,500	2,000
Less than 1 year \| Silver [Member]
Property, plant, equipment and development costs
Commodity price estimates	40	26
Less than 1 year \| Copper [Member]
Property, plant, equipment and development costs
Commodity price estimates \| $ / t	10,500	8,900
Less than 1 year \| Lead [Member]
Property, plant, equipment and development costs
Commodity price estimates	1,900	1,900
Less than 1 year \| Zinc [Member]
Property, plant, equipment and development costs
Commodity price estimates \| $ / t	2,900	2,500
Between 1 and 3 years \| Gold per ounce [Member]
Property, plant, equipment and development costs
Commodity price estimates		2,304
Between 1 and 3 years \| Silver [Member]
Property, plant, equipment and development costs
Commodity price estimates		30
Between 1 and 3 years \| Copper [Member]
Property, plant, equipment and development costs
Commodity price estimates \| $ / t		10,175
Between 1 and 3 years \| Lead [Member]
Property, plant, equipment and development costs
Commodity price estimates		2,185
Between 1 and 3 years \| Zinc [Member]
Property, plant, equipment and development costs
Commodity price estimates \| $ / t		2,721
Between 1 and 20 years \| Gold per ounce [Member]
Property, plant, equipment and development costs
Commodity price estimates	4,146
Between 1 and 20 years \| Silver [Member]
Property, plant, equipment and development costs
Commodity price estimates	53
Between 1 and 20 years \| Copper [Member]
Property, plant, equipment and development costs
Commodity price estimates \| $ / t	13,334
Between 1 and 20 years \| Lead [Member]
Property, plant, equipment and development costs
Commodity price estimates	2,622
Between 1 and 20 years \| Zinc [Member]
Property, plant, equipment and development costs
Commodity price estimates \| $ / t	3,416