Annual report pursuant to Section 13 and 15(d)

GOODWILL AND OTHER INTANGIBLE ASSETS AND LIABILITIES (Narrative) (Details)

v3.3.1.900
GOODWILL AND OTHER INTANGIBLE ASSETS AND LIABILITIES (Narrative) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Goodwill [Line Items]      
Goodwill, Impairment Loss $ 0.0 $ 73.5  
Product $ 1,832.4 3,095.2 $ 3,631.8
Below-market sales contracts, remaining contract life 1 year    
Future Below Market Sales Contracts Revenue Year One $ 23.1    
Cost of Sales [Member]      
Goodwill [Line Items]      
Amortization expense relating to intangible assets 4.2 8.4 8.4
Sales Revenue, Goods, Net [Member] | Sales Revenue, Goods, Net [Member]      
Goodwill [Line Items]      
Product 23.1 23.1 $ 26.9
Permits [Member]      
Goodwill [Line Items]      
Impairment of Intangible Assets, Finite-lived 0.0 13.8  
Asia Pacific Iron Ore [Member]      
Goodwill [Line Items]      
Goodwill, Impairment Loss $ 0.0 $ 73.5