Quarterly report pursuant to Section 13 or 15(d)

SUPPLEMENTARY GUARANTOR INFORMATION (Supplementary Statements of Condensed Consolidating Operations and Comprehensive Income) (Details)

v3.10.0.1
SUPPLEMENTARY GUARANTOR INFORMATION (Supplementary Statements of Condensed Consolidating Operations and Comprehensive Income) (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Sep. 30, 2018
Sep. 30, 2017
Revenue from Contract with Customer, Including Assessed Tax $ 684.7     $ 530.7     $ 1,525.9 $ 1,195.0
Freight and venture partners' cost reimbursements 57.1     66.0     110.2 159.2
Revenues 741.8     596.7     1,636.1 1,354.2
COST OF GOODS SOLD AND OPERATING EXPENSES (480.2)     (438.9)     (1,028.5) (1,002.7)
SALES MARGIN 261.6     157.8     607.6 351.5
Selling, general and administrative expenses (30.1)     (23.8)     (81.4) (75.5)
Miscellaneous - net (6.0)     (5.3)     (16.2) 1.3
Other operating expense (36.1)     (29.1)     (97.6) (74.2)
OPERATING INCOME 225.5     128.7     510.0 277.3
Interest expense, net (29.5)     (27.6)     (93.1) (99.1)
Gain (loss) on extinguishment of debt 0.0     (88.6)     0.2 (165.4)
Other non-operating income 4.3     2.6     13.1 7.6
TOTAL OTHER INCOME (EXPENSE) (25.2)     (113.6)     (79.8) (256.9)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES 200.3     15.1     430.2 20.4
Income Tax Expense (Benefit) (0.5)     7.2     (14.4) 7.2
Equity in income (loss) of subsidiaries 0.0     0.0     0.0 0.0
INCOME FROM CONTINUING OPERATIONS 199.8     22.3     415.8 27.6
INCOME FROM DISCONTINUED OPERATIONS, NET OF TAX 238.0     30.6     102.8 25.6
NET INCOME 437.8 $ 165.1 $ (84.3) 52.9 $ 30.1 $ (29.8) 518.6 53.2
LOSS ATTRIBUTABLE TO NONCONTROLLING INTEREST 0.0     0.5     0.0 3.9
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS 437.8     53.4     518.6 57.1
Other comprehensive income (loss) (221.2)     2.3     (204.4) 4.2
TOTAL COMPREHENSIVE INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS 216.6     55.7     314.2 61.3
Reportable Legal Entities [Member] | Cliffs Shareholders Equity [Member]                
Revenue from Contract with Customer, Including Assessed Tax 0.0     0.0     0.0 0.0
Freight and venture partners' cost reimbursements 0.0     0.0     0.0 0.0
Revenues 0.0     0.0     0.0 0.0
COST OF GOODS SOLD AND OPERATING EXPENSES 0.0     0.0     0.0 0.0
SALES MARGIN 0.0     0.0     0.0 0.0
Selling, general and administrative expenses (23.1)     (18.7)     (62.9) (57.9)
Miscellaneous - net 0.0     (1.4)     (0.4) (2.3)
Other operating expense (23.1)     (20.1)     (63.3) (60.2)
OPERATING INCOME (23.1)     (20.1)     (63.3) (60.2)
Interest expense, net (29.2)     (27.8)     (91.9) (99.8)
Gain (loss) on extinguishment of debt       (88.6)     0.2 (165.4)
Other non-operating income (0.9)     (1.0)     (2.6) (3.0)
TOTAL OTHER INCOME (EXPENSE) (30.1)     (117.4)     (94.3) (268.2)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES (53.2)     (137.5)     (157.6) (328.4)
Income Tax Expense (Benefit) (0.3)     7.3     (13.8) 7.5
Equity in income (loss) of subsidiaries 471.0     150.5     665.7 393.5
INCOME FROM CONTINUING OPERATIONS 417.5     20.3     494.3 72.6
INCOME FROM DISCONTINUED OPERATIONS, NET OF TAX 20.3     33.1     24.3 (15.5)
NET INCOME       53.4       57.1
LOSS ATTRIBUTABLE TO NONCONTROLLING INTEREST       0.0       0.0
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS 437.8     53.4     518.6 57.1
Other comprehensive income (loss) (221.2)     2.3     (204.4) 4.2
TOTAL COMPREHENSIVE INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS 216.6     55.7     314.2 61.3
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]                
Revenue from Contract with Customer, Including Assessed Tax 684.7     530.7     1,525.9 1,195.0
Freight and venture partners' cost reimbursements 57.1     66.0     110.2 159.2
Revenues 741.8     596.7     1,636.1 1,354.2
COST OF GOODS SOLD AND OPERATING EXPENSES (480.2)     (438.9)     (1,028.5) (1,002.7)
SALES MARGIN 261.6     157.8     607.6 351.5
Selling, general and administrative expenses (6.7)     (4.3)     (17.8) (14.4)
Miscellaneous - net (5.5)     (4.1)     (14.4) (13.3)
Other operating expense (12.2)     (8.4)     (32.2) (27.7)
OPERATING INCOME 249.4     149.4     575.4 323.8
Interest expense, net (0.4)     0.0     (1.8) 0.0
Gain (loss) on extinguishment of debt       0.0     0.0 0.0
Other non-operating income 0.1     (0.6)     0.8 (2.2)
TOTAL OTHER INCOME (EXPENSE) (0.3)     (0.6)     (1.0) (2.2)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES 249.1     148.8     574.4 321.6
Income Tax Expense (Benefit) 0.0     0.0     (0.2) 0.0
Equity in income (loss) of subsidiaries 4.7     3.5     13.8 10.1
INCOME FROM CONTINUING OPERATIONS 253.8     152.3     588.0 331.7
INCOME FROM DISCONTINUED OPERATIONS, NET OF TAX 12.9     0.2     12.8 1.1
NET INCOME       152.5       332.8
LOSS ATTRIBUTABLE TO NONCONTROLLING INTEREST       0.5       3.9
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS 266.7     153.0     600.8 336.7
Other comprehensive income (loss) 6.1     (84.3)     18.0 (67.8)
TOTAL COMPREHENSIVE INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS 272.8     68.7     618.8 268.9
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]                
Revenue from Contract with Customer, Including Assessed Tax 0.0     0.0     0.0 0.0
Freight and venture partners' cost reimbursements 0.0     0.0     0.0 0.0
Revenues 0.0     0.0     0.0 0.0
COST OF GOODS SOLD AND OPERATING EXPENSES 0.0     0.0     0.0 0.0
SALES MARGIN 0.0     0.0     0.0 0.0
Selling, general and administrative expenses (0.3)     (0.8)     (0.7) (3.2)
Miscellaneous - net (0.5)     0.2     (1.4) 16.9
Other operating expense (0.8)     (0.6)     (2.1) 13.7
OPERATING INCOME (0.8)     (0.6)     (2.1) 13.7
Interest expense, net 0.1     0.2     0.6 0.7
Gain (loss) on extinguishment of debt       0.0     0.0 0.0
Other non-operating income 5.1     4.2     14.9 12.8
TOTAL OTHER INCOME (EXPENSE) 5.2     4.4     15.5 13.5
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES 4.4     3.8     13.4 27.2
Income Tax Expense (Benefit) (0.2)     (0.1)     (0.4) (0.3)
Equity in income (loss) of subsidiaries 0.0     0.0     0.0 0.0
INCOME FROM CONTINUING OPERATIONS 4.2     3.7     13.0 26.9
INCOME FROM DISCONTINUED OPERATIONS, NET OF TAX 204.8     (2.7)     65.7 40.0
NET INCOME       1.0       66.9
LOSS ATTRIBUTABLE TO NONCONTROLLING INTEREST       0.0       0.0
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS 209.0     1.0     78.7 66.9
Other comprehensive income (loss) (230.5)     1.8     (227.5) (17.5)
TOTAL COMPREHENSIVE INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS (21.5)     2.8     (148.8) 49.4
Consolidation, Eliminations [Member]                
Revenue from Contract with Customer, Including Assessed Tax 0.0     0.0     0.0 0.0
Freight and venture partners' cost reimbursements 0.0     0.0     0.0 0.0
Revenues 0.0     0.0     0.0 0.0
COST OF GOODS SOLD AND OPERATING EXPENSES 0.0     0.0     0.0 0.0
SALES MARGIN 0.0     0.0     0.0 0.0
Selling, general and administrative expenses 0.0     0.0     0.0 0.0
Miscellaneous - net 0.0     0.0     0.0 0.0
Other operating expense 0.0     0.0     0.0 0.0
OPERATING INCOME 0.0     0.0     0.0 0.0
Interest expense, net 0.0     0.0     0.0 0.0
Gain (loss) on extinguishment of debt       0.0     0.0 0.0
Other non-operating income 0.0     0.0     0.0 0.0
TOTAL OTHER INCOME (EXPENSE) 0.0     0.0     0.0 0.0
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES 0.0     0.0     0.0 0.0
Income Tax Expense (Benefit) 0.0     0.0     0.0 0.0
Equity in income (loss) of subsidiaries (475.7)     (154.0)     (679.5) (403.6)
INCOME FROM CONTINUING OPERATIONS (475.7)     (154.0)     (679.5) (403.6)
INCOME FROM DISCONTINUED OPERATIONS, NET OF TAX 0.0     0.0     0.0 0.0
NET INCOME       (154.0)       (403.6)
LOSS ATTRIBUTABLE TO NONCONTROLLING INTEREST       0.0       0.0
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS (475.7)     (154.0)     (679.5) (403.6)
Other comprehensive income (loss) 224.4     82.5     209.5 85.3
TOTAL COMPREHENSIVE INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS $ (251.3)     $ (71.5)     $ (470.0) $ (318.3)