COMMITMENTS AND CONTINGENCIES: - Environmental matters (Details) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2011 person category
Environmental costs
Environmental capital investment	$ 47.4	$ 30.1
Peru
Environmental costs
Environmental capital investment	3.5	2.9
Mexico
Environmental costs
Environmental capital investment	$ 43.9	$ 27.2
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