Quarterly report pursuant to Section 13 or 15(d)

SUPPLEMENTARY GUARANTOR INFORMATION (Supplementary Statements of Condensed Consolidating Financial Position) (Details)

v3.10.0.1
SUPPLEMENTARY GUARANTOR INFORMATION (Supplementary Statements of Condensed Consolidating Financial Position) (Details) - USD ($)
$ in Millions
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Jan. 01, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Cash and cash equivalents $ 897.1     $ 978.3 $ 978.3 $ 227.1      
Accounts receivable, net 141.4     183.3 106.7        
Inventories 187.9     87.0 138.4        
Supplies and other inventories 88.2     88.8 88.8        
Income tax receivable 110.3     13.3 13.3        
Derivative assets 190.8     49.5 37.9        
Current assets of discontinued operations 16.1     118.5 118.5        
Loans to and accounts receivable from the Canadian Entities 0.0     51.6 51.6        
Other current assets 18.8     11.1 11.1        
TOTAL CURRENT ASSETS 1,650.6     1,581.4 1,544.6        
PROPERTY, PLANT AND EQUIPMENT, NET 1,144.8     1,033.8 1,033.8        
Deposits for property, plant and equipment 94.6     17.8 17.8        
Income tax receivable 113.6       235.3        
Non-current assets of discontinued operations 0.0     20.3 20.3        
Investment in subsidiaries 0.0       0.0        
Long-term intercompany notes 0.0       0.0        
Other non-current assets 121.4     101.6 101.6        
TOTAL OTHER ASSETS 329.6     375.0 375.0        
Assets 3,125.0     2,990.2 2,953.4        
Accounts payable 140.8     100.9 99.5        
Accrued expenses 95.1     79.1 79.1        
Accrued interest 26.2     31.4 31.4        
Contingent claims 0.0     55.6 55.6        
Partnership distribution payable 43.1     44.2 44.2        
Current liabilities of discontinued operations 14.2     75.0 75.0        
Other current liabilities 61.3     68.8 67.4        
TOTAL CURRENT LIABILITIES 380.7     455.0 452.2        
PENSION AND POSTEMPLOYMENT BENEFIT LIABILITIES 225.0     257.7 257.7        
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 174.4     167.7 167.7        
LONG-TERM DEBT 2,300.0     2,304.2 2,304.2        
NON-CURRENT LIABILITIES OF DISCONTINUED OPERATIONS 9.3     52.2 52.2        
LONG-TERM INTERCOMPANY NOTES 0.0       0.0        
OTHER LIABILITIES 121.8     163.5 163.5        
Liabilities 3,211.2     3,400.3 3,397.5        
TOTAL CLIFFS SHAREHOLDERS' DEFICIT (86.2)     (410.3) (444.3)        
NONCONTROLLING INTEREST 0.0     0.2 0.2        
TOTAL DEFICIT (86.2) $ (306.3) $ (484.8) (410.1) (444.1) $ (833.1) $ (666.7) $ (703.0) $ (1,330.5)
TOTAL LIABILITIES AND DEFICIT 3,125.0     $ 2,990.2 2,953.4        
Consolidation, Eliminations [Member]                  
Cash and cash equivalents 0.0       0.0        
Accounts receivable, net (3.9)       (0.7)        
Inventories 0.0       0.0        
Supplies and other inventories 0.0       0.0        
Income tax receivable 0.0       0.0        
Derivative assets 0.0       0.0        
Current assets of discontinued operations 0.0       0.0        
Loans to and accounts receivable from the Canadian Entities         0.0        
Other current assets 0.0       0.0        
TOTAL CURRENT ASSETS (3.9)       (0.7)        
PROPERTY, PLANT AND EQUIPMENT, NET 0.0       0.0        
Deposits for property, plant and equipment 0.0       0.0        
Income tax receivable 0.0       0.0        
Non-current assets of discontinued operations         0.0        
Investment in subsidiaries (1,363.8)       (1,054.2)        
Long-term intercompany notes (121.3)       (242.0)        
Other non-current assets 0.0       0.0        
TOTAL OTHER ASSETS (1,485.1)       (1,296.2)        
Assets (1,489.0)       (1,296.9)        
Accounts payable (3.9)       (0.7)        
Accrued expenses 0.0       0.0        
Accrued interest 0.0       0.0        
Contingent claims         0.0        
Partnership distribution payable 0.0       0.0        
Current liabilities of discontinued operations 0.0       0.0        
Other current liabilities 0.0       0.0        
TOTAL CURRENT LIABILITIES (3.9)       (0.7)        
PENSION AND POSTEMPLOYMENT BENEFIT LIABILITIES 0.0       0.0        
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 0.0       0.0        
LONG-TERM DEBT 0.0       0.0        
NON-CURRENT LIABILITIES OF DISCONTINUED OPERATIONS 0.0       0.0        
LONG-TERM INTERCOMPANY NOTES (121.3)       (242.0)        
OTHER LIABILITIES 0.0       0.0        
Liabilities (125.2)       (242.7)        
TOTAL CLIFFS SHAREHOLDERS' DEFICIT (1,363.8)       (1,054.2)        
NONCONTROLLING INTEREST         0.0        
TOTAL DEFICIT (1,363.8)       (1,054.2)        
TOTAL LIABILITIES AND DEFICIT (1,489.0)       (1,296.9)        
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]                  
Cash and cash equivalents 2.7       27.3        
Accounts receivable, net 0.1       0.0        
Inventories 0.0       0.0        
Supplies and other inventories 0.0       0.0        
Income tax receivable 0.2       0.0        
Derivative assets 0.0       0.0        
Current assets of discontinued operations 16.1       118.5        
Loans to and accounts receivable from the Canadian Entities         0.0        
Other current assets 0.6       0.5        
TOTAL CURRENT ASSETS 19.7       146.3        
PROPERTY, PLANT AND EQUIPMENT, NET 50.8       50.8        
Deposits for property, plant and equipment 14.6       9.6        
Income tax receivable 0.0       0.0        
Non-current assets of discontinued operations         20.3        
Investment in subsidiaries 0.0       0.0        
Long-term intercompany notes 121.3       242.0        
Other non-current assets 1.7       2.0        
TOTAL OTHER ASSETS 137.6       273.9        
Assets 208.1       471.0        
Accounts payable 4.1       0.8        
Accrued expenses 0.2       0.2        
Accrued interest 0.0       0.0        
Contingent claims         0.0        
Partnership distribution payable 0.0       0.0        
Current liabilities of discontinued operations 10.2       75.0        
Other current liabilities 1.8       1.8        
TOTAL CURRENT LIABILITIES 16.3       77.8        
PENSION AND POSTEMPLOYMENT BENEFIT LIABILITIES (254.4)       (239.3)        
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 26.8       27.1        
LONG-TERM DEBT 0.0       0.0        
NON-CURRENT LIABILITIES OF DISCONTINUED OPERATIONS 9.3       52.2        
LONG-TERM INTERCOMPANY NOTES 0.0       0.0        
OTHER LIABILITIES 0.5       0.6        
Liabilities (201.5)       (81.6)        
TOTAL CLIFFS SHAREHOLDERS' DEFICIT 409.6       552.4        
NONCONTROLLING INTEREST         0.2        
TOTAL DEFICIT 409.6       552.6        
TOTAL LIABILITIES AND DEFICIT 208.1       471.0        
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]                  
Cash and cash equivalents 1.9       2.1        
Accounts receivable, net 137.4       102.9        
Inventories 187.9       138.4        
Supplies and other inventories 88.2       88.8        
Income tax receivable 0.0       1.9        
Derivative assets 190.6       37.9        
Current assets of discontinued operations 0.0       0.0        
Loans to and accounts receivable from the Canadian Entities         6.9        
Other current assets 10.3       5.6        
TOTAL CURRENT ASSETS 616.3       384.5        
PROPERTY, PLANT AND EQUIPMENT, NET 1,079.7       965.5        
Deposits for property, plant and equipment 80.0       8.2        
Income tax receivable 3.7       0.0        
Non-current assets of discontinued operations         0.0        
Investment in subsidiaries 38.3       29.9        
Long-term intercompany notes 0.0       0.0        
Other non-current assets 111.2       91.8        
TOTAL OTHER ASSETS 233.2       129.9        
Assets 1,929.2       1,479.9        
Accounts payable 136.5       92.3        
Accrued expenses 78.2       59.9        
Accrued interest 0.0       0.0        
Contingent claims         0.0        
Partnership distribution payable 43.1       44.2        
Current liabilities of discontinued operations 0.0       0.0        
Other current liabilities 57.7       63.5        
TOTAL CURRENT LIABILITIES 315.5       259.9        
PENSION AND POSTEMPLOYMENT BENEFIT LIABILITIES 415.1       430.6        
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 147.6       140.6        
LONG-TERM DEBT 0.0       0.0        
NON-CURRENT LIABILITIES OF DISCONTINUED OPERATIONS 0.0       0.0        
LONG-TERM INTERCOMPANY NOTES 0.0       0.0        
OTHER LIABILITIES 96.9       147.2        
Liabilities 975.1       978.3        
TOTAL CLIFFS SHAREHOLDERS' DEFICIT 954.1       501.6        
NONCONTROLLING INTEREST         0.0        
TOTAL DEFICIT 954.1       501.6        
TOTAL LIABILITIES AND DEFICIT 1,929.2       1,479.9        
Reportable Legal Entities [Member] | Cliffs Shareholders Equity [Member]                  
Cash and cash equivalents 892.5       948.9        
Accounts receivable, net 7.8       4.5        
Inventories 0.0       0.0        
Supplies and other inventories 0.0       0.0        
Income tax receivable 110.1       11.4        
Derivative assets 0.2       0.0        
Current assets of discontinued operations 0.0       0.0        
Loans to and accounts receivable from the Canadian Entities         44.7        
Other current assets 7.9       5.0        
TOTAL CURRENT ASSETS 1,018.5       1,014.5        
PROPERTY, PLANT AND EQUIPMENT, NET 14.3       17.5        
Deposits for property, plant and equipment 0.0       0.0        
Income tax receivable 109.9       235.3        
Non-current assets of discontinued operations         0.0        
Investment in subsidiaries 1,325.5       1,024.3        
Long-term intercompany notes 0.0       0.0        
Other non-current assets 8.5       7.8        
TOTAL OTHER ASSETS 1,443.9       1,267.4        
Assets 2,476.7       2,299.4        
Accounts payable 4.1       7.1        
Accrued expenses 16.7       19.0        
Accrued interest 26.2       31.4        
Contingent claims         55.6        
Partnership distribution payable 0.0       0.0        
Current liabilities of discontinued operations 4.0       0.0        
Other current liabilities 1.8       2.1        
TOTAL CURRENT LIABILITIES 52.8       115.2        
PENSION AND POSTEMPLOYMENT BENEFIT LIABILITIES 64.3       66.4        
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 0.0       0.0        
LONG-TERM DEBT 2,300.0       2,304.2        
NON-CURRENT LIABILITIES OF DISCONTINUED OPERATIONS 0.0       0.0        
LONG-TERM INTERCOMPANY NOTES 121.3       242.0        
OTHER LIABILITIES 24.4       15.7        
Liabilities 2,562.8       2,743.5        
TOTAL CLIFFS SHAREHOLDERS' DEFICIT (86.1)       (444.1)        
NONCONTROLLING INTEREST         0.0        
TOTAL DEFICIT (86.1)       (444.1)        
TOTAL LIABILITIES AND DEFICIT $ 2,476.7       $ 2,299.4