Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.1
SUPPLEMENTARY GUARANTOR INFORMATION (Supplementary Statements of Condensed Consolidating Financial Position) (Details) - USD ($)
$ in Millions
Mar. 31, 2019
Dec. 31, 2018
Mar. 31, 2018
Dec. 31, 2017
Cash and cash equivalents $ 430.2 $ 823.2 $ 757.2 $ 978.3
Accounts receivable, net 20.1 226.7    
Inventories 312.7 87.9    
Supplies and other inventories 97.3 93.2    
Derivative assets 107.4 91.5    
Income tax receivable, current 117.3 117.3    
Other current assets 41.0 39.8    
TOTAL CURRENT ASSETS 1,126.0 1,479.6    
PROPERTY, PLANT AND EQUIPMENT, NET 1,410.3 1,286.0    
Deposits for property, plant and equipment 68.3 83.0    
Income tax receivable, non-current 121.3 121.3    
Deferred income tax assets 466.6 464.8    
Investment in subsidiaries 0.0 0.0    
Long-term intercompany notes 0.0 0.0    
Other non-current assets 113.8 94.9    
TOTAL OTHER ASSETS 770.0 764.0    
TOTAL ASSETS 3,306.3 3,529.6    
Accounts payable 171.7 186.8    
Accrued employment costs 42.1 74.0    
Accrued interest 23.0 38.4    
Partnership distribution payable 43.8 43.5    
Other current liabilities 113.4 125.5    
TOTAL CURRENT LIABILITIES 394.0 468.2    
PENSION AND POSTEMPLOYMENT BENEFIT LIABILITIES 244.2 248.7    
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 174.4 172.0    
LONG-TERM DEBT 2,087.0 2,092.9    
LONG-TERM INTERCOMPANY NOTES 0.0 0.0    
OTHER LIABILITIES 145.0 123.6    
TOTAL LIABILITIES 3,044.6 3,105.4    
Stockholders' Equity Attributable to Parent 261.7 424.2    
TOTAL LIABILITIES AND EQUITY 3,306.3 3,529.6    
Consolidation, Eliminations [Member]        
Cash and cash equivalents 0.0 0.0 0.0 0.0
Accounts receivable, net (4.0) (4.1)    
Inventories 0.0 0.0    
Supplies and other inventories 0.0 0.0    
Derivative assets 0.0 0.0    
Income tax receivable, current 0.0 0.0    
Other current assets 0.0 0.0    
TOTAL CURRENT ASSETS (4.0) (4.1)    
PROPERTY, PLANT AND EQUIPMENT, NET 0.0 0.0    
Deposits for property, plant and equipment 0.0 0.0    
Income tax receivable, non-current 0.0 0.0    
Deferred income tax assets 0.0 0.0    
Investment in subsidiaries (1,478.6) (1,313.1)    
Long-term intercompany notes (121.3) (121.3)    
Other non-current assets 0.0 0.0    
TOTAL OTHER ASSETS (1,599.9) (1,434.4)    
TOTAL ASSETS (1,603.9) (1,438.5)    
Accounts payable (4.0) (4.1)    
Accrued employment costs 0.0 0.0    
Accrued interest 0.0 0.0    
Partnership distribution payable 0.0 0.0    
Other current liabilities 0.0 0.0    
TOTAL CURRENT LIABILITIES (4.0) (4.1)    
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    
LONG-TERM INTERCOMPANY NOTES (121.3) (121.3)    
OTHER LIABILITIES 0.0 0.0    
TOTAL LIABILITIES (125.3) (125.4)    
Stockholders' Equity Attributable to Parent (1,478.6) (1,313.1)    
TOTAL LIABILITIES AND EQUITY (1,603.9) (1,438.5)    
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]        
Cash and cash equivalents 2.7 2.7 2.6 27.3
Accounts receivable, net 0.3 0.3    
Inventories 0.0 0.0    
Supplies and other inventories 0.0 0.0    
Derivative assets 0.0 0.0    
Income tax receivable, current 0.0 0.0    
Other current assets 11.3 12.9    
TOTAL CURRENT ASSETS 14.3 15.9    
PROPERTY, PLANT AND EQUIPMENT, NET 50.8 50.8    
Deposits for property, plant and equipment 14.7 14.6    
Income tax receivable, non-current 0.0 0.0    
Deferred income tax assets 1.2 1.2    
Investment in subsidiaries 0.0 0.0    
Long-term intercompany notes 121.3 121.3    
Other non-current assets 1.4 1.5    
TOTAL OTHER ASSETS 138.6 138.6    
TOTAL ASSETS 203.7 205.3    
Accounts payable 4.1 4.2    
Accrued employment costs 0.1 0.1    
Accrued interest 0.0 0.0    
Partnership distribution payable 0.0 0.0    
Other current liabilities 7.1 8.2    
TOTAL CURRENT LIABILITIES 11.3 12.5    
PENSION AND POSTEMPLOYMENT BENEFIT LIABILITIES (234.7) (230.0)    
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 19.8 19.9    
LONG-TERM DEBT 0.0 0.0    
LONG-TERM INTERCOMPANY NOTES 0.0 0.0    
OTHER LIABILITIES 7.9 8.8    
TOTAL LIABILITIES (195.7) (188.8)    
Stockholders' Equity Attributable to Parent 399.4 394.1    
TOTAL LIABILITIES AND EQUITY 203.7 205.3    
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]        
Cash and cash equivalents 0.7 0.7 1.0 2.1
Accounts receivable, net 16.2 221.3    
Inventories 312.7 87.9    
Supplies and other inventories 97.3 93.2    
Derivative assets 106.7 91.4    
Income tax receivable, current 0.0 0.0    
Other current assets 21.1 16.9    
TOTAL CURRENT ASSETS 554.7 511.4    
PROPERTY, PLANT AND EQUIPMENT, NET 1,347.5 1,221.9    
Deposits for property, plant and equipment 53.6 68.4    
Income tax receivable, non-current 4.1 4.1    
Deferred income tax assets 0.0 0.0    
Investment in subsidiaries 30.1 50.8    
Long-term intercompany notes 0.0 0.0    
Other non-current assets 95.8 85.4    
TOTAL OTHER ASSETS 183.6 208.7    
TOTAL ASSETS 2,085.8 1,942.0    
Accounts payable 166.4 181.4    
Accrued employment costs 32.6 45.4    
Accrued interest 0.0 0.0    
Partnership distribution payable 43.8 43.5    
Other current liabilities 78.4 86.7    
TOTAL CURRENT LIABILITIES 321.2 357.0    
PENSION AND POSTEMPLOYMENT BENEFIT LIABILITIES 414.8 414.4    
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 154.6 152.1    
LONG-TERM DEBT 0.0 0.0    
LONG-TERM INTERCOMPANY NOTES 0.0 0.0    
OTHER LIABILITIES 116.0 99.5    
TOTAL LIABILITIES 1,006.6 1,023.0    
Stockholders' Equity Attributable to Parent 1,079.2 919.0    
TOTAL LIABILITIES AND EQUITY 2,085.8 1,942.0    
Reportable Legal Entities [Member] | Cliffs Shareholders Equity [Member]        
Cash and cash equivalents 426.8 819.8 $ 753.6 $ 948.9
Accounts receivable, net 7.6 9.2    
Inventories 0.0 0.0    
Supplies and other inventories 0.0 0.0    
Derivative assets 0.7 0.1    
Income tax receivable, current 117.3 117.3    
Other current assets 8.6 10.0    
TOTAL CURRENT ASSETS 561.0 956.4    
PROPERTY, PLANT AND EQUIPMENT, NET 12.0 13.3    
Deposits for property, plant and equipment 0.0 0.0    
Income tax receivable, non-current 117.2 117.2    
Deferred income tax assets 465.4 463.6    
Investment in subsidiaries 1,448.5 1,262.3    
Long-term intercompany notes 0.0 0.0    
Other non-current assets 16.6 8.0    
TOTAL OTHER ASSETS 2,047.7 1,851.1    
TOTAL ASSETS 2,620.7 2,820.8    
Accounts payable 5.2 5.3    
Accrued employment costs 9.4 28.5    
Accrued interest 23.0 38.4    
Partnership distribution payable 0.0 0.0    
Other current liabilities 27.9 30.6    
TOTAL CURRENT LIABILITIES 65.5 102.8    
PENSION AND POSTEMPLOYMENT BENEFIT LIABILITIES 64.1 64.3    
ENVIRONMENTAL AND MINE CLOSURE OBLIGATIONS 0.0 0.0    
LONG-TERM DEBT 2,087.0 2,092.9    
LONG-TERM INTERCOMPANY NOTES 121.3 121.3    
OTHER LIABILITIES 21.1 15.3    
TOTAL LIABILITIES 2,359.0 2,396.6    
Stockholders' Equity Attributable to Parent 261.7 424.2    
TOTAL LIABILITIES AND EQUITY $ 2,620.7 $ 2,820.8