SUPPLEMENTARY MINERAL RESERVE INFORMATION (UNAUDITED) (Details) oz in Millions, lb in Millions	12 Months Ended
	Dec. 31, 2019 lb oz $ / lb $ / oz
Copper
Estimated Recoverable Proven And Probable Reserves	120,000
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	29.6
Long Term Average Price Used To Estimate Recoverable Reserves | $ / oz	1,200
Three Year Average Price | $ / oz	1,306
Molybdenum
Estimated Recoverable Proven And Probable Reserves	3,640
Long Term Average Price Used To Estimate Recoverable Reserves | $ / lb	10
Three Year Average Price | $ / lb	10.50
Silver
Long Term Average Price Used To Estimate Recoverable Reserves | $ / oz	15
Consolidated Basis [Member] | Copper
Estimated Recoverable Proven And Probable Reserves	116,000
Consolidated Basis [Member] | Gold
Estimated Recoverable Proven And Probable Reserves | oz	29.6
Consolidated Basis [Member] | Molybdenum
Estimated Recoverable Proven And Probable Reserves	3,580
Consolidated Basis [Member] | Silver
Estimated Recoverable Proven And Probable Reserves | oz	375.0
Consolidated Basis [Member] | Indonesia | Copper
Estimated Recoverable Proven And Probable Reserves	35,600
Consolidated Basis [Member] | Indonesia | Gold
Estimated Recoverable Proven And Probable Reserves | oz	29.1
Consolidated Basis [Member] | Indonesia | Molybdenum
Estimated Recoverable Proven And Probable Reserves	0