Annual report pursuant to Section 13 and 15(d)

NEW ACCOUNTING STANDARDS NEW ACCOUNTING STANDARDS (Schedule of Accounting Change) (Details)

v3.10.0.1
NEW ACCOUNTING STANDARDS NEW ACCOUNTING STANDARDS (Schedule of Accounting Change) (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                        
Product revenues                 $ 2,172.3 $ 1,644.6 $ 1,379.7  
Freight and Reimbursement Revenue                 160.1 221.4 174.8  
Revenues $ 696.3 $ 741.8 $ 714.3 $ 180.0 $ 511.8 $ 596.7 $ 471.3 $ 286.2 2,332.4 1,866.0 1,554.5  
Cost of Goods and Services Sold                 (1,522.8) (1,398.4) (1,274.4)  
SALES MARGIN 202.0 261.6 284.5 61.5 116.1 157.8 144.7 49.0 809.6 467.6 280.1  
Selling, general and administrative expenses                 (116.8) (102.9) (115.8)  
Miscellaneous - net                 (19.6) 25.5 (33.6)  
Operating Expenses                 (136.4) (77.4) (149.4)  
OPERATING INCOME                 673.2 390.2 130.7  
Interest expense, net                 (118.9) (126.8) (193.9)  
Gain (loss) on extinguishment of debt                 (6.8) (165.4) 166.3  
Other non-operating income                 17.2 10.2 7.3  
TOTAL OTHER INCOME (EXPENSE)                 (108.5) (282.0) (20.3)  
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES                 564.7 108.2 110.4  
Income Tax Expense (Benefit)                 (475.2) (252.4) (12.2)  
Income (loss) from continuing operations         333.0 22.3 83.8 (78.5) 1,039.9 360.6 122.6  
INCOME FROM DISCONTINUED OPERATIONS, net of tax (14.6) 238.0 (64.3) (70.9) (23.1) 30.6 (53.7) 48.7 88.2 2.5 76.7  
INCOME FROM DISCONTINUED OPERATIONS, net of tax                 88.2 2.5 76.7  
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS $ 609.5 $ 437.8 $ 165.1 $ (84.3) $ 309.9 $ 53.4 $ 31.8 $ (28.1) $ 1,128.1 $ 367.0 $ 174.1  
Continuing operations $ 2.11 $ 0.67 $ 0.77 $ (0.05) $ 1.12 $ 0.08 $ 0.28 $ (0.29) $ 3.50 $ 1.27 $ 0.49  
Discontinued operations (0.05) 0.80 (0.22) (0.24) (0.08) 0.10 (0.18) 0.18 0.30 0.01 0.39  
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Basic: 2.06 1.47 0.55 (0.29) 1.04 0.18 0.10 (0.11) 3.80 1.28 0.88  
Continuing operations 2.03 0.64 0.76 (0.05) 1.11 0.08 0.28 (0.29) 3.42 1.25 0.49  
Discontinued operations (0.05) 0.77 (0.21) (0.24) (0.08) 0.10 (0.18) 0.18 0.29 0.01 0.38  
Earnings per common share attributable to Cliffs common shareholders - diluted: $ 1.98 $ 1.41 $ 0.55 $ (0.29) $ 1.03 $ 0.18 $ 0.10 $ (0.11) $ 3.71 $ 1.26 $ 0.87  
Basic                 297.2 288.4 197.7  
Diluted                 304.1 293.0 200.1  
Cash and cash equivalents $ 823.2       $ 978.3       $ 823.2 $ 978.3   $ 978.3
Accounts receivable, net 226.7       106.7       226.7 106.7   183.3
Inventories 87.9       138.4       87.9 138.4   87.0
Supplies and other inventories 93.2       88.8       93.2 88.8   88.8
Derivative assets 91.5       37.9       91.5 37.9   49.5
Income tax receivable, current 117.3       13.3       117.3 13.3   13.3
Current assets of discontinued operations 12.4       118.5       12.4 118.5   118.5
Other current assets 27.4       11.1       27.4 11.1   11.1
TOTAL CURRENT ASSETS 1,479.6       1,544.6       1,479.6 1,544.6   1,581.4
PROPERTY, PLANT AND EQUIPMENT, NET 1,286.0       1,033.8       1,286.0 1,033.8   1,033.8
Deposits for property, plant and equipment 83.0       17.8       83.0 17.8   17.8
Income tax receivable, non-current 121.3       235.3       121.3 235.3   235.3
Deferred income taxes 464.8       0.0       464.8 0.0    
Other non-current assets 94.9       101.6       94.9 101.6   101.6
TOTAL OTHER ASSETS 764.0       375.0       764.0 375.0   375.0
TOTAL ASSETS 3,529.6       2,953.4       3,529.6 2,953.4 $ 1,923.9 2,990.2
Accounts payable 186.8       99.5       186.8 99.5   100.9
Accrued employment costs 74.0       52.7       74.0 52.7   52.7
State and local taxes payable 35.5       30.2       35.5 30.2   30.2
Accrued interest 38.4       31.4       38.4 31.4   31.4
Partnership distribution payable 43.5       44.2       43.5 44.2   44.2
Current liabilities of discontinued operations 6.7       75.0       6.7 75.0   75.0
Other current liabilities 83.3       63.6       83.3 63.6   65.0
TOTAL CURRENT LIABILITIES 468.2       452.2       468.2 452.2   455.0
TOTAL POSTEMPLOYMENT BENEFIT LIABILITIES 248.7       257.7       248.7 257.7   257.7
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 172.0       167.7       172.0 167.7   167.7
LONG-TERM DEBT 2,092.9       2,304.2       2,092.9 2,304.2   2,304.2
NON-CURRENT LIABILITIES OF DISCONTINUED OPERATIONS 8.3       52.2       8.3 52.2   52.2
OTHER LIABILITIES 115.3       163.5       115.3 163.5   163.5
TOTAL LIABILITIES 3,105.4       3,397.5       3,105.4 3,397.5   3,400.3
TOTAL CLIFFS SHAREHOLDERS' EQUITY (DEFICIT) 424.2       (444.3)       424.2 (444.3)   (410.3)
TOTAL LIABILITIES AND EQUITY (DEFICIT) 3,529.6       $ 2,953.4       3,529.6 $ 2,953.4   2,990.2
Calculated under Revenue Guidance in Effect before Topic 606 [Member]                        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                        
Product revenues                 2,108.1      
Freight and Reimbursement Revenue                 156.2      
Revenues                 2,264.3      
Cost of Goods and Services Sold                 (1,513.2)      
SALES MARGIN                 751.1      
Selling, general and administrative expenses                 (116.8)      
Miscellaneous - net                 (19.6)      
Operating Expenses                 (136.4)      
OPERATING INCOME                 614.7      
Interest expense, net                 (118.9)      
Gain (loss) on extinguishment of debt                 (6.8)      
Other non-operating income                 17.2      
TOTAL OTHER INCOME (EXPENSE)                 (108.5)      
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES                 506.2      
Income Tax Expense (Benefit)                 (487.5)      
Income (loss) from continuing operations                 993.7      
INCOME FROM DISCONTINUED OPERATIONS, net of tax                 88.2      
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS                 $ 1,081.9      
Continuing operations                 $ 3.34      
Discontinued operations                 0.30      
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Basic:                 3.64      
Continuing operations                 3.27      
Discontinued operations                 0.29      
Earnings per common share attributable to Cliffs common shareholders - diluted:                 $ 3.56      
Basic                 297.2      
Diluted                 304.1      
Cash and cash equivalents 823.2               $ 823.2      
Accounts receivable, net 108.7               108.7      
Inventories 141.3               141.3      
Supplies and other inventories 93.2               93.2      
Derivative assets 60.7               60.7      
Income tax receivable, current 117.3               117.3      
Current assets of discontinued operations 12.4               12.4      
Other current assets 27.4               27.4      
TOTAL CURRENT ASSETS 1,384.2               1,384.2      
PROPERTY, PLANT AND EQUIPMENT, NET 1,286.0               1,286.0      
Deposits for property, plant and equipment 83.0               83.0      
Income tax receivable, non-current 121.3               121.3      
Deferred income taxes 477.1               477.1      
Other non-current assets 94.9               94.9      
TOTAL OTHER ASSETS 776.3               776.3      
TOTAL ASSETS 3,446.5               3,446.5      
Accounts payable 184.9               184.9      
Accrued employment costs 74.0               74.0      
State and local taxes payable 35.5               35.5      
Accrued interest 38.4               38.4      
Partnership distribution payable 43.5               43.5      
Current liabilities of discontinued operations 6.7               6.7      
Other current liabilities 83.7               83.7      
TOTAL CURRENT LIABILITIES 466.7               466.7      
TOTAL POSTEMPLOYMENT BENEFIT LIABILITIES 248.7               248.7      
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 172.0               172.0      
LONG-TERM DEBT 2,092.9               2,092.9      
NON-CURRENT LIABILITIES OF DISCONTINUED OPERATIONS 8.3               8.3      
OTHER LIABILITIES 115.3               115.3      
TOTAL LIABILITIES 3,103.9               3,103.9      
TOTAL CLIFFS SHAREHOLDERS' EQUITY (DEFICIT) 342.6               342.6      
TOTAL LIABILITIES AND EQUITY (DEFICIT) 3,446.5               3,446.5      
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]                        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                        
Product revenues                 64.2      
Freight and Reimbursement Revenue                 3.9      
Revenues                 68.1      
Cost of Goods and Services Sold                 (9.6)      
SALES MARGIN                 58.5      
Selling, general and administrative expenses                 0.0      
Miscellaneous - net                 0.0      
Operating Expenses                 0.0      
OPERATING INCOME                 58.5      
Interest expense, net                 0.0      
Gain (loss) on extinguishment of debt                 0.0      
Other non-operating income                 0.0      
TOTAL OTHER INCOME (EXPENSE)                 0.0      
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES                 58.5      
Income Tax Expense (Benefit)                 12.3      
Income (loss) from continuing operations                 46.2      
INCOME FROM DISCONTINUED OPERATIONS, net of tax                 0.0      
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS                 $ 46.2      
Continuing operations                 $ 0.16      
Discontinued operations                 0.00      
Earnings (Loss) per Common Share Attributable to Cliffs Common Shareholders - Basic:                 0.16      
Continuing operations                 0.15      
Discontinued operations                 0.00      
Earnings per common share attributable to Cliffs common shareholders - diluted:                 $ 0.15      
Cash and cash equivalents 0.0               $ 0.0     0.0
Accounts receivable, net 118.0               118.0     76.6
Inventories (53.4)               (53.4)     (51.4)
Supplies and other inventories 0.0               0.0     0.0
Derivative assets 30.8               30.8     11.6
Income tax receivable, current 0.0               0.0     0.0
Current assets of discontinued operations 0.0               0.0     0.0
Other current assets 0.0               0.0     0.0
TOTAL CURRENT ASSETS 95.4               95.4     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, non-current 0.0               0.0     0.0
Deferred income taxes (12.3)               (12.3)      
Other non-current assets 0.0               0.0     0.0
TOTAL OTHER ASSETS (12.3)               (12.3)     0.0
TOTAL ASSETS 83.1               83.1     36.8
Accounts payable 1.9               1.9     1.4
Accrued employment costs 0.0               0.0     0.0
State and local taxes payable 0.0               0.0     0.0
Accrued interest 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 (0.4)               (0.4)     1.4
TOTAL CURRENT LIABILITIES 1.5               1.5     2.8
TOTAL 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
TOTAL LIABILITIES 1.5               1.5     2.8
TOTAL CLIFFS SHAREHOLDERS' EQUITY (DEFICIT) 81.6               81.6     34.0
TOTAL LIABILITIES AND EQUITY (DEFICIT) $ 83.1               $ 83.1     $ 36.8