Annual report pursuant to Section 13 and 15(d)

INVENTORIES (Narrative) (Details)

v3.6.0.2
INVENTORIES (Narrative) (Details) - USD ($)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Inventory [Line Items]    
Cost of Goods Sold $ 8,800,000  
Asia Pacific Iron Ore [Member]    
Inventory [Line Items]    
Other Inventory, Noncurrent 0 $ 6,800,000
U.S. Iron Ore [Member]    
Inventory [Line Items]    
Inventory, LIFO Reserve $ 78,500,000 87,800,000
Increase in Inventories due to build up of LIFO layers   $ 118,800,000