COMMITMENTS AND CONTINGENCIES: - Environmental matters (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2011 person category
Environmental costs
Environmental capital investment	$ 108.3	$ 61.4	$ 68.7
Peru
Environmental costs
Environmental capital investment	7.7	8.7	6.4
Mexico
Environmental costs
Environmental capital investment	$ 100.6	$ 52.7	$ 62.3
Number of categories of collective actions | category				3
Minimum number of people claiming injury due to collective action initiative in Civil Federal Procedures Code (CFPC) | person				30