Annual report pursuant to Section 13 and 15(d)

QUARTERLY RESULTS OF OPERATIONS (Details)

v3.6.0.2
QUARTERLY RESULTS OF OPERATIONS (Details) - USD ($)
shares in Millions, $ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2016
Sep. 30, 2016
Dec. 31, 2015
Mar. 31, 2014
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount           25.3 25.2
Antidilutive Incremental Common Shares Excluded and Attributable to Share-based Payment Arrangements 0.0 3.0         0.7
Loss (gain) on sale of North American Coal mines       $ 155.0      
Sale Price of CLCC Assets       $ 174.0      
Income Tax Expense (Benefit)         $ (12.2) $ 169.3 $ (86.0)
Asset Impairment Charges         $ 0.0 $ 3.3 $ 635.5
Minimum [Member]              
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount     25.2        
Antidilutive Incremental Common Shares Excluded and Attributable to Share-based Payment Arrangements     0.1        
Maximum [Member]              
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount           25.6  
Antidilutive Incremental Common Shares Excluded and Attributable to Share-based Payment Arrangements           0.3