Annual report pursuant to Section 13 and 15(d)

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

v3.10.0.1
SUPPLEMENTARY GUARANTOR INFORMATION (Supplementary Statements of Condensed Consolidating Operations and Comprehensive Income (Loss) (Details) - USD ($)
$ 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
REVENUES FROM PRODUCT SALES AND SERVICES                      
Product revenues                 $ 2,172.3 $ 1,644.6 $ 1,379.7
Freight and Reimbursement Revenue                 160.1 221.4 174.8
TOTAL REVENUES FROM PRODUCT SALES AND SERVICES $ 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 SOLD AND OPERATING EXPENSES                 (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
OTHER OPERATING INCOME (EXPENSE)                      
Selling, general and administrative expenses                 (116.8) (102.9) (115.8)
Miscellaneous - net                 (19.6) 25.5 (33.6)
Other operating expense                 (136.4) (77.4) (149.4)
OPERATING INCOME                 673.2 390.2 130.7
OTHER INCOME (EXPENSE)                      
Interest expense, net                 (118.9) (126.8) (193.9)
Gain (loss) on extinguishment/restructuring 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 AND EQUITY LOSS FROM VENTURES                 564.7 108.2 110.4
INCOME TAX BENEFIT (EXPENSE)                 475.2 252.4 12.2
EQUITY IN INCOME OF SUBSIDIARIES                 0.0 0.0 0.0
INCOME 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                 88.2 2.5 76.7
NET INCOME                 1,128.1 363.1 199.3
INCOME ATTRIBUTABLE TO NONCONTROLLING INTEREST                 0.0 3.9 (25.2)
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
OTHER COMPREHENSIVE INCOME (LOSS)                 (244.9) (4.0) (3.3)
TOTAL COMPREHENSIVE INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS                 883.2 363.0 170.8
Consolidation, Eliminations [Member]                      
REVENUES FROM PRODUCT SALES AND SERVICES                      
Product revenues                 0.0 0.0 0.0
Freight and Reimbursement Revenue                 0.0 0.0 0.0
TOTAL REVENUES FROM PRODUCT SALES AND SERVICES                 0.0 0.0 0.0
COST OF GOODS SOLD AND OPERATING EXPENSES                 0.0 0.0 0.0
SALES MARGIN                 0.0 0.0 0.0
OTHER OPERATING INCOME (EXPENSE)                      
Selling, general and administrative expenses                 0.0 0.0 0.0
Miscellaneous - net                 0.0 0.0 0.0
Other operating expense                 0.0 0.0 0.0
OPERATING INCOME                 0.0 0.0 0.0
OTHER INCOME (EXPENSE)                      
Interest expense, net                 0.0 0.0 0.0
Gain (loss) on extinguishment/restructuring of debt                 0.0 0.0 0.0
Other non-operating income                 0.0 0.0 0.0
TOTAL OTHER INCOME (EXPENSE)                 0.0 0.0 0.0
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES AND EQUITY LOSS FROM VENTURES                 0.0 0.0 0.0
INCOME TAX BENEFIT (EXPENSE)                 0.0 0.0 0.0
EQUITY IN INCOME OF SUBSIDIARIES                 (883.7) (524.4) (332.8)
INCOME FROM CONTINUING OPERATIONS                 (883.7) (524.4) (332.8)
INCOME FROM DISCONTINUED OPERATIONS, net of tax                 0.0 0.0 0.0
NET INCOME                   (524.4) (332.8)
INCOME ATTRIBUTABLE TO NONCONTROLLING INTEREST                   0.0 0.0
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS                 (883.7) (524.4) (332.8)
OTHER COMPREHENSIVE INCOME (LOSS)                 280.8 (8.1) 5.3
TOTAL COMPREHENSIVE INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS                 (602.9) (532.5) (327.5)
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]                      
REVENUES FROM PRODUCT SALES AND SERVICES                      
Product revenues                 0.0 0.0 0.0
Freight and Reimbursement Revenue                 0.0 0.0 0.0
TOTAL REVENUES FROM PRODUCT SALES AND SERVICES                 0.0 0.0 0.0
COST OF GOODS SOLD AND OPERATING EXPENSES                 0.0 0.0 0.0
SALES MARGIN                 0.0 0.0 0.0
OTHER OPERATING INCOME (EXPENSE)                      
Selling, general and administrative expenses                 (0.3) (5.8) (3.5)
Miscellaneous - net                 4.3 16.8 (15.6)
Other operating expense                 4.0 11.0 (19.1)
OPERATING INCOME                 4.0 11.0 (19.1)
OTHER INCOME (EXPENSE)                      
Interest expense, net                 0.8 1.0 0.5
Gain (loss) on extinguishment/restructuring of debt                 0.0 0.0 0.0
Other non-operating income                 19.8 17.2 16.4
TOTAL OTHER INCOME (EXPENSE)                 20.6 18.2 16.9
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES AND EQUITY LOSS FROM VENTURES                 24.6 29.2 (2.2)
INCOME TAX BENEFIT (EXPENSE)                 0.5 (0.3) 4.9
EQUITY IN INCOME OF SUBSIDIARIES                 0.0 0.0 0.0
INCOME FROM CONTINUING OPERATIONS                 25.1 28.9 2.7
INCOME FROM DISCONTINUED OPERATIONS, net of tax                 66.4 22.1 91.2
NET INCOME                   51.0 93.9
INCOME ATTRIBUTABLE TO NONCONTROLLING INTEREST                   0.0 0.0
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS                 91.5 51.0 93.9
OTHER COMPREHENSIVE INCOME (LOSS)                 (256.7) (4.8) 15.4
TOTAL COMPREHENSIVE INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS                 (165.2) 46.2 109.3
Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]                      
REVENUES FROM PRODUCT SALES AND SERVICES                      
Product revenues                 2,172.3 1,644.6 1,379.7
Freight and Reimbursement Revenue                 160.1 221.4 174.8
TOTAL REVENUES FROM PRODUCT SALES AND SERVICES                 2,332.4 1,866.0 1,554.5
COST OF GOODS SOLD AND OPERATING EXPENSES                 (1,522.8) (1,398.4) (1,274.4)
SALES MARGIN                 809.6 467.6 280.1
OTHER OPERATING INCOME (EXPENSE)                      
Selling, general and administrative expenses                 (30.4) (19.9) (18.0)
Miscellaneous - net                 (23.6) 11.0 (12.4)
Other operating expense                 (54.0) (8.9) (30.4)
OPERATING INCOME                 755.6 458.7 249.7
OTHER INCOME (EXPENSE)                      
Interest expense, net                 (2.1) (1.0) 0.1
Gain (loss) on extinguishment/restructuring of debt                 0.0 0.0 0.0
Other non-operating income                 0.9 (3.0) (5.0)
TOTAL OTHER INCOME (EXPENSE)                 (1.2) (4.0) (4.9)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES AND EQUITY LOSS FROM VENTURES                 754.4 454.7 244.8
INCOME TAX BENEFIT (EXPENSE)                 0.0 1.3 3.0
EQUITY IN INCOME OF SUBSIDIARIES                 25.5 11.8 13.7
INCOME FROM CONTINUING OPERATIONS                 779.9 467.8 261.5
INCOME FROM DISCONTINUED OPERATIONS, net of tax                 12.3 1.7 2.6
NET INCOME                   469.5 264.1
INCOME ATTRIBUTABLE TO NONCONTROLLING INTEREST                   3.9 (25.2)
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS                 792.2 473.4 238.9
OTHER COMPREHENSIVE INCOME (LOSS)                 (24.1) 12.9 (20.7)
TOTAL COMPREHENSIVE INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS                 768.1 486.3 218.2
Parent [Member] | Reportable Legal Entities [Member]                      
REVENUES FROM PRODUCT SALES AND SERVICES                      
Product revenues                 0.0 0.0 0.0
Freight and Reimbursement Revenue                 0.0 0.0 0.0
TOTAL REVENUES FROM PRODUCT SALES AND SERVICES                 0.0 0.0 0.0
COST OF GOODS SOLD AND OPERATING EXPENSES                 0.0 0.0 0.0
SALES MARGIN                 0.0 0.0 0.0
OTHER OPERATING INCOME (EXPENSE)                      
Selling, general and administrative expenses                 (86.1) (77.2) (94.3)
Miscellaneous - net                 (0.3) (2.3) (5.6)
Other operating expense                 (86.4) (79.5) (99.9)
OPERATING INCOME                 (86.4) (79.5) (99.9)
OTHER INCOME (EXPENSE)                      
Interest expense, net                 (117.6) (126.8) (194.5)
Gain (loss) on extinguishment/restructuring of debt                 (6.8) (165.4) 166.3
Other non-operating income                 (3.5) (4.0) (4.1)
TOTAL OTHER INCOME (EXPENSE)                 (127.9) (296.2) (32.3)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES AND EQUITY LOSS FROM VENTURES                 (214.3) (375.7) (132.2)
INCOME TAX BENEFIT (EXPENSE)                 474.7 251.4 4.3
EQUITY IN INCOME OF SUBSIDIARIES                 858.2 512.6 319.1
INCOME FROM CONTINUING OPERATIONS                 1,118.6 388.3 191.2
INCOME FROM DISCONTINUED OPERATIONS, net of tax                 9.5 (21.3) (17.1)
NET INCOME                   367.0 174.1
INCOME ATTRIBUTABLE TO NONCONTROLLING INTEREST                   0.0 0.0
NET INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS                 1,128.1 367.0 174.1
OTHER COMPREHENSIVE INCOME (LOSS)                 (244.9) (4.0) (3.3)
TOTAL COMPREHENSIVE INCOME ATTRIBUTABLE TO CLIFFS SHAREHOLDERS                 $ 883.2 $ 363.0 $ 170.8