Quarterly report pursuant to Section 13 or 15(d)

EARNINGS PER SHARE (Earnings Per Share Computation) (Details)

v3.8.0.1
EARNINGS PER SHARE (Earnings Per Share Computation) (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Income (Loss) from Continuing Operations $ 20.6 $ (25.1) $ 66.8 $ 119.1
Net Income (Loss) Attributable to Noncontrolling Interest (0.5) (2.0) (3.9) 23.5
Net Income (Loss) from Continuing Operations Attributable to Cliffs Shareholders 21.1 (23.1) 70.7 95.6
INCOME (LOSS) FROM DISCONTINUED OPERATIONS, NET OF TAX 32.3 (2.7) (13.6) (0.6)
NET INCOME (LOSS) ATTRIBUTABLE TO CLIFFS SHAREHOLDERS $ 53.4 $ (25.8) $ 57.1 $ 95.0
Weighted Average Number of Shares:        
Basic 296.1 206.3 285.8 186.5
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements 5.0 0.0 4.7 2.0
Diluted 301.1 206.3 290.5 188.5
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Basic:        
Continuing operations (in dollars per share) $ 0.07 $ (0.11) $ 0.25 $ 0.51
Discontinued operations (in dollars per share) 0.11 (0.01) (0.05) 0.00
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Basic (in dollars per share) 0.18 (0.12) 0.20 0.51
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Diluted:        
Continuing operations (in dollars per share) 0.07 (0.11) 0.24 0.51
Discontinued operations (in dollars per share) 0.11 (0.01) (0.05) 0.00
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Diluted (in dollars per share) $ 0.18 $ (0.12) $ 0.19 $ 0.51