SUPPLEMENTARY MINERAL RESERVE INFORMATION (UNAUDITED) (Details) oz in Millions, lb in Millions	12 Months Ended
	Dec. 31, 2020 lb oz $ / oz $ / lb
Copper
Estimated Recoverable Proven And Probable Reserves	117,200
Long Term Average Price Used To Estimate Recoverable Reserves | $ / lb	2.50
Three Year Average Price | $ / lb	2.83
Gold
Estimated Recoverable Proven And Probable Reserves | oz	28.9
Long Term Average Price Used To Estimate Recoverable Reserves | $ / oz	1,200
Three Year Average Price | $ / oz	1,477
Molybdenum
Estimated Recoverable Proven And Probable Reserves	3,770
Long Term Average Price Used To Estimate Recoverable Reserves | $ / lb	10
Three Year Average Price | $ / lb	10.65
Silver
Long Term Average Price Used To Estimate Recoverable Reserves | $ / oz	15
Consolidated Basis [Member] | Copper
Estimated Recoverable Proven And Probable Reserves	113,200
Consolidated Basis [Member] | Gold
Estimated Recoverable Proven And Probable Reserves | oz	28.9
Consolidated Basis [Member] | Molybdenum
Estimated Recoverable Proven And Probable Reserves	3,710
Consolidated Basis [Member] | Silver
Estimated Recoverable Proven And Probable Reserves | oz	362.0
Consolidated Basis [Member] | Indonesia | Copper
Estimated Recoverable Proven And Probable Reserves	33,400
Consolidated Basis [Member] | Indonesia | Gold
Estimated Recoverable Proven And Probable Reserves | oz	28.3
Consolidated Basis [Member] | Indonesia | Molybdenum
Estimated Recoverable Proven And Probable Reserves	0