Quarterly report pursuant to Section 13 or 15(d)

NEW ACCOUNTING STANDARDS (Schedule of New Accounting Pronouncements and Changes in Accounting Principles) (Details)

v3.10.0.1
NEW ACCOUNTING STANDARDS (Schedule of New Accounting Pronouncements and Changes in Accounting Principles) (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Jan. 01, 2018
Dec. 31, 2017
Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
Cash and cash equivalents $ 802.5 $ 270.4 $ 802.5 $ 270.4 $ 978.3 $ 978.3  
Accounts receivable, net 152.6   152.6   183.3 106.7  
Inventories (256.4)   (256.4)   (87.0) (138.4)  
Supplies and other inventories 88.6   88.6   88.8 88.8  
Derivative assets 174.7   174.7   49.5 37.9  
Current assets of discontinued operations 45.3   45.3   118.5 118.5  
Loans to and accounts receivable from the Canadian Entities 0.0   0.0   51.6 51.6  
Other current assets 26.8   26.8   24.4 24.4  
TOTAL CURRENT ASSETS 1,546.9   1,546.9   1,581.4 1,544.6  
PROPERTY, PLANT AND EQUIPMENT, NET 1,081.3   1,081.3   1,033.8 1,033.8  
Deposits for property, plant and equipment 85.7   85.7   17.8 17.8  
Income tax receivable 219.9   219.9   235.3 235.3  
Non-current assets of discontinued operations 0.0   0.0   20.3 20.3  
Other non-current assets 117.7   117.7   101.6 101.6  
TOTAL OTHER ASSETS 423.3   423.3   375.0 375.0  
Assets 3,051.5   3,051.5   2,990.2 2,953.4  
Accounts payable 119.0   119.0   100.9 99.5  
Accrued expenses 85.1   85.1   79.1 79.1  
Accrued interest 43.1   43.1   31.4 31.4  
Contingent claims 0.0   0.0   55.6 55.6  
Partnership distribution payable 44.2   44.2   44.2 44.2  
Current liabilities of discontinued operations 117.3   117.3   75.0 75.0  
Other current liabilities (66.2)   (66.2)   (68.8) (67.4)  
Liabilities, Current (474.9)   (474.9)   (455.0) (452.2)  
PENSION AND POSTEMPLOYMENT BENEFIT LIABILITIES 245.0   245.0   257.7 257.7  
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 172.3   172.3   167.7 167.7  
LONG-TERM DEBT 2,297.0   2,297.0   2,304.2 2,304.2  
NON-CURRENT LIABILITIES OF DISCONTINUED OPERATIONS 10.3   10.3   52.2 52.2  
OTHER LIABILITIES 158.3   158.3   163.5 163.5  
Liabilities (3,357.8)   (3,357.8)   (3,400.3) (3,397.5)  
TOTAL CLIFFS SHAREHOLDERS' DEFICIT (306.3)   (306.3)   (410.3) (444.3)  
NONCONTROLLING INTEREST 0.0   0.0   0.2 0.2  
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest (306.3) (666.7) (306.3) (666.7) (410.1) (444.1) $ (1,330.5)
TOTAL LIABILITIES AND DEFICIT 3,051.5   3,051.5   2,990.2 $ 2,953.4  
Product 672.0 417.0 841.2 664.3      
Freight and venture partners' cost reimbursements 42.3 54.3 53.1 93.2      
Revenues 714.3 471.3 894.3 757.5      
COST OF GOODS SOLD AND OPERATING EXPENSES (429.8) (326.6) (548.3) (563.8)      
SALES MARGIN 284.5 144.7 346.0 193.7      
Selling, general and administrative expenses (26.2) (26.6) (51.3) (51.7)      
Miscellaneous - net (4.1) (2.9) (10.2) 6.6      
Other operating expense (30.3) (29.5) (61.5) (45.1)      
OPERATING INCOME 254.2 115.2 284.5 148.6      
Interest expense, net (31.2) (30.1) (63.6) (71.5)      
Gain (loss) on extinguishment of debt 0.2 (4.9) 0.2 (76.8)      
Other non-operating income 4.4 2.5 8.8 5.0      
TOTAL OTHER INCOME (EXPENSE) (26.6) (32.5) (54.6) (143.3)      
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES 227.6 82.7 229.9 5.3      
INCOME TAX BENEFIT (EXPENSE) 1.8 1.1 (13.9) 0.0      
INCOME FROM CONTINUING OPERATIONS 229.4 83.8 216.0 5.3      
LOSS FROM DISCONTINUED OPERATIONS, NET OF TAX (64.3) (53.7) (135.2) (5.0)      
NET INCOME 165.1 30.1 80.8 0.3      
LOSS ATTRIBUTABLE TO NONCONTROLLING INTEREST 0.0 1.7 0.0 3.4      
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS $ 165.1 $ 31.8 $ 80.8 $ 3.7      
Continuing operations (in dollars per share) $ 0.77 $ 0.28 $ 0.73 $ 0.03      
Discontinued operations (in dollars per share) (0.22) (0.18) (0.46) (0.01)      
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Basic (in dollars per share) 0.55 0.10 0.27 0.02      
Continuing operations (in dollars per share) 0.76 0.28 0.72 0.03      
Discontinued operations (in dollars per share) (0.21) (0.18) (0.45) (0.02)      
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Diluted (in dollars per share) $ 0.55 $ 0.10 $ 0.27 $ 0.01      
Basic 297,618 296,100 297,442 280,617      
Diluted 301,275 300,700 301,143 285,247      
Scenario, Previously Reported [Member]              
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
COST OF GOODS SOLD AND OPERATING EXPENSES   $ (327.1)   $ (564.9)      
Selling, general and administrative expenses   (24.7)   (47.8)      
Miscellaneous - net   (2.6)   7.3      
OPERATING INCOME   116.9   152.1      
Other non-operating income   0.8   1.5      
NET INCOME   30.1   0.3      
Accounting Standards Update 2017-07 [Member]              
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
COST OF GOODS SOLD AND OPERATING EXPENSES   (0.5)   (1.1)      
Selling, general and administrative expenses   1.9   3.9      
Miscellaneous - net   (0.3)   (0.7)      
OPERATING INCOME   (1.7)   (3.5)      
Other non-operating income   1.7   3.5      
NET INCOME   $ 0.0   $ 0.0      
Calculated under Revenue Guidance in Effect before Topic 606 [Member]              
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
Cash and cash equivalents $ 802.5   $ 802.5        
Accounts receivable, net 53.0   53.0        
Inventories (323.9)   (323.9)        
Supplies and other inventories 88.6   88.6        
Derivative assets 146.2   146.2        
Current assets of discontinued operations 45.3   45.3        
Loans to and accounts receivable from the Canadian Entities 0.0   0.0        
Other current assets 26.8   26.8        
TOTAL CURRENT ASSETS 1,486.3   1,486.3        
PROPERTY, PLANT AND EQUIPMENT, NET 1,081.3   1,081.3        
Deposits for property, plant and equipment 85.7   85.7        
Income tax receivable 219.9   219.9        
Non-current assets of discontinued operations 0.0   0.0        
Other non-current assets 117.7   117.7        
TOTAL OTHER ASSETS 423.3   423.3        
Assets 2,990.9   2,990.9        
Accounts payable 117.8   117.8        
Accrued expenses 85.1   85.1        
Accrued interest 43.1   43.1        
Contingent claims 0.0   0.0        
Partnership distribution payable 44.2   44.2        
Current liabilities of discontinued operations 117.3   117.3        
Other current liabilities (72.1)   (72.1)        
Liabilities, Current (479.6)   (479.6)        
PENSION AND POSTEMPLOYMENT BENEFIT LIABILITIES 245.0   245.0        
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 172.3   172.3        
LONG-TERM DEBT 2,297.0   2,297.0        
NON-CURRENT LIABILITIES OF DISCONTINUED OPERATIONS 10.3   10.3        
OTHER LIABILITIES 158.3   158.3        
Liabilities (3,362.5)   (3,362.5)        
TOTAL CLIFFS SHAREHOLDERS' DEFICIT (371.6)   (371.6)        
NONCONTROLLING INTEREST 0.0   0.0        
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest (371.6)   (371.6)        
TOTAL LIABILITIES AND DEFICIT 2,990.9   2,990.9        
Product 568.0   795.6        
Freight and venture partners' cost reimbursements 36.3   51.2        
Revenues 604.3   846.8        
COST OF GOODS SOLD AND OPERATING EXPENSES (368.6)   (530.7)        
SALES MARGIN 235.7   316.1        
Selling, general and administrative expenses (26.2)   (51.3)        
Miscellaneous - net     (10.2)        
Other operating expense (30.3)   (61.5)        
OPERATING INCOME 205.4   254.6        
Interest expense, net (31.2)   (63.6)        
Gain (loss) on extinguishment of debt 0.2   0.2        
Other non-operating income 4.4   8.8        
TOTAL OTHER INCOME (EXPENSE) (26.6)   (54.6)        
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES 178.8   200.0        
INCOME TAX BENEFIT (EXPENSE) 1.8   (13.9)        
INCOME FROM CONTINUING OPERATIONS 180.6   186.1        
LOSS FROM DISCONTINUED OPERATIONS, NET OF TAX (64.3)   (135.2)        
NET INCOME 116.3   50.9        
LOSS ATTRIBUTABLE TO NONCONTROLLING INTEREST 0.0   0.0        
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS $ 116.3   $ 50.9        
Continuing operations (in dollars per share) $ 0.61   $ 0.62        
Discontinued operations (in dollars per share) (0.22)   (0.45)        
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Basic (in dollars per share) 0.39   0.17        
Continuing operations (in dollars per share) 0.60   0.62        
Discontinued operations (in dollars per share) (0.21)   (0.45)        
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Diluted (in dollars per share) $ 0.39   $ 0.17        
Basic 297,618   297,442        
Diluted 301,275   301,143        
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]              
New Accounting Pronouncements or Change in Accounting Principle [Line Items]              
Cash and cash equivalents $ 0.0   $ 0.0   0.0    
Accounts receivable, net 99.6   99.6   76.6    
Inventories (67.5)   (67.5)   (51.4)    
Supplies and other inventories 0.0   0.0   0.0    
Derivative assets 28.5   28.5   11.6    
Current assets of discontinued operations 0.0   0.0   0.0    
Loans to and accounts receivable from the Canadian Entities 0.0   0.0   0.0    
Other current assets 0.0   0.0   0.0    
TOTAL CURRENT ASSETS 60.6   60.6   36.8    
PROPERTY, PLANT AND EQUIPMENT, NET 0.0   0.0   0.0    
Deposits for property, plant and equipment 0.0   0.0   0.0    
Income tax receivable 0.0   0.0   0.0    
Non-current assets of discontinued operations 0.0   0.0   0.0    
Other non-current assets 0.0   0.0   0.0    
TOTAL OTHER ASSETS 0.0   0.0   0.0    
Assets 60.6   60.6   36.8    
Accounts payable 1.2   1.2   1.4    
Accrued expenses 0.0   0.0   0.0    
Accrued interest 0.0   0.0   0.0    
Contingent claims 0.0   0.0   0.0    
Partnership distribution payable 0.0   0.0   0.0    
Current liabilities of discontinued operations 0.0   0.0   0.0    
Other current liabilities (5.9)   (5.9)   (1.4)    
Liabilities, Current (4.7)   (4.7)   (2.8)    
PENSION AND POSTEMPLOYMENT BENEFIT LIABILITIES 0.0   0.0   0.0    
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 0.0   0.0   0.0    
LONG-TERM DEBT 0.0   0.0   0.0    
NON-CURRENT LIABILITIES OF DISCONTINUED OPERATIONS 0.0   0.0   0.0    
OTHER LIABILITIES 0.0   0.0   0.0    
Liabilities (4.7)   (4.7)   (2.8)    
TOTAL CLIFFS SHAREHOLDERS' DEFICIT 65.3   65.3   34.0    
NONCONTROLLING INTEREST 0.0   0.0   0.0    
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest 65.3   65.3   34.0    
TOTAL LIABILITIES AND DEFICIT 60.6   60.6   $ 36.8    
Product 104.0   45.6        
Freight and venture partners' cost reimbursements 6.0   1.9        
Revenues 110.0   47.5        
COST OF GOODS SOLD AND OPERATING EXPENSES (61.2)   (17.6)        
SALES MARGIN 48.8   29.9        
Selling, general and administrative expenses 0.0   0.0        
Miscellaneous - net 0.0   0.0        
Other operating expense 0.0   0.0        
OPERATING INCOME 48.8   29.9        
Interest expense, net 0.0   0.0        
Gain (loss) on extinguishment of debt 0.0   0.0        
Other non-operating income 0.0   0.0        
TOTAL OTHER INCOME (EXPENSE) 0.0   0.0        
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES 48.8   29.9        
INCOME TAX BENEFIT (EXPENSE) 0.0   0.0        
INCOME FROM CONTINUING OPERATIONS 48.8   29.9        
LOSS FROM DISCONTINUED OPERATIONS, NET OF TAX 0.0   0.0        
NET INCOME 48.8   29.9        
LOSS ATTRIBUTABLE TO NONCONTROLLING INTEREST 0.0   0.0        
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS $ 48.8   $ 29.9        
Continuing operations (in dollars per share) $ 0.16   $ 0.10        
Discontinued operations (in dollars per share) 0.00   0.00        
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Basic (in dollars per share) 0.16   0.10        
Continuing operations (in dollars per share) 0.16   0.10        
Discontinued operations (in dollars per share) 0.00   0.00        
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Diluted (in dollars per share) $ 0.16   $ 0.10