COMMITMENTS AND CONTINGENCIES: - Environmental matters (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2011 category person
Environmental costs
Environmental capital investment	$ 43.7	$ 25.9
Peru
Environmental costs
Environmental capital investment	1.6	2.7
Mexico
Environmental costs
Environmental capital investment	$ 42.1	$ 23.2
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