PROVISIONALLY PRICED SALES: (Details) - Jun. 30, 2015 lb in Millions, $ in Millions	USD ($) lb $ / item
In July 2015
PROVISIONALLY PRICED SALES:
Reduction of sales as effect of market price	$ 11.7
After July 2015
PROVISIONALLY PRICED SALES:
Reduction in sales as effect of forward price	$ 10.9
Copper | April and May 2015
PROVISIONALLY PRICED SALES:
Nonmonetary notional amount of commodity (in million lbs.) | lb	123.3
Provisional price | $ / item	2.62
Molybdenum | April To July 2015
PROVISIONALLY PRICED SALES:
Nonmonetary notional amount of commodity (in million lbs.) | lb	17.1
Provisional price | $ / item	6.25