Annual report pursuant to Section 13 and 15(d)

SEGMENT REPORTING (Schedule Of Segment Reporting Information, By Segment) (Details)

v2.4.0.6
SEGMENT REPORTING (Schedule Of Segment Reporting Information, By Segment) (Details) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 12 Months Ended
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2011
Sep. 30, 2011
Jun. 30, 2011
Mar. 31, 2011
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Segment Reporting Information [Line Items]                      
Revenues from product sales and services $ 1,535.9 $ 1,544.9 $ 1,579.5 $ 1,212.4 $ 1,603.7 $ 2,089.1 $ 1,723.2 $ 1,147.9 $ 5,872.7 $ 6,563.9 $ 4,483.8
Revenues from product sales and services, percent                 100.00% 100.00% 100.00%
Sales margin 238.5 198.3 443.5 291.8 480.1 843.1 699.2 588.5 1,172.1 2,610.9 1,458.7
Other operating expense                 (1,480.9) (314.1) (225.9)
Other income (expense)                 (193.0) (106.3) 33.6
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES AND EQUITY INCOME (LOSS) FROM VENTURES                 (501.8) 2,190.5 1,266.4
Depreciation, depletion and amortization                 525.8 426.9 322.3
Capital additions                 1,335.3 [1] 960.9 [1] 275.8 [1]
Assets 13,574.9       14,541.7       13,574.9 14,541.7 7,778.2
Operating Segments [Member]
                      
Segment Reporting Information [Line Items]                      
Assets 13,295.2       14,008.1       13,295.2 14,008.1 6,243.6
U.S. Iron Ore [Member]
                      
Segment Reporting Information [Line Items]                      
Revenues from product sales and services                 2,723.3 3,509.9 2,443.7
Revenues from product sales and services, percent                 46.00% 53.00% 54.00%
Sales margin                 976.2 1,679.3 788.4
Depreciation, depletion and amortization                 100.9 86.2 61.7
Capital additions                 168.8 [1] 191.4 [1] 84.7 [1]
Assets 1,735.1       1,691.8       1,735.1 1,691.8 1,537.1
Eastern Canadian Iron Ore [Member]
                      
Segment Reporting Information [Line Items]                      
Revenues from product sales and services                 1,008.9 1,178.1 477.7
Revenues from product sales and services, percent                 17.00% 18.00% 11.00%
Sales margin                 (121.4) 290.9 133.6
Depreciation, depletion and amortization                 160.2 124.6 41.9
Capital additions                 865.2 [1] 303.1 [1] 18.8 [1]
Assets 7,605.1       7,973.1       7,605.1 7,973.1 629.6
Asia Pacific Iron Ore [Member]
                      
Segment Reporting Information [Line Items]                      
Revenues from product sales and services                 1,259.3 1,363.5 1,123.9
Revenues from product sales and services, percent                 22.00% 21.00% 25.00%
Sales margin                 311.0 699.5 566.2
Depreciation, depletion and amortization                 151.9 100.9 133.9
Capital additions                 87.7 [1] 262.0 [1] 53.6 [1]
Assets 1,506.3       1,511.2       1,506.3 1,511.2 1,195.3
North American Coal [Member]
                      
Segment Reporting Information [Line Items]                      
Revenues from product sales and services                 881.1 512.1 438.2
Revenues from product sales and services, percent                 15.00% 8.00% 10.00%
Sales margin                 (1.8) (58.4) (28.6)
Depreciation, depletion and amortization                 98.2 86.5 60.4
Capital additions                 144.1 [1] 181.0 [1] 89.5 [1]
Assets 1,877.8       1,814.4       1,877.8 1,814.4 1,623.8
All Other Segments [Member]
                      
Segment Reporting Information [Line Items]                      
Revenues from product sales and services                 0.1 0.3 0.3
Revenues from product sales and services, percent                 0.00% 0.00% 0.00%
Sales margin                 8.1 (0.4) (0.9)
Depreciation, depletion and amortization                 14.6 28.7 24.4
Capital additions                 69.5 [1] 23.4 [1] 29.2 [1]
Assets 570.9       1,017.6       570.9 1,017.6 1,257.8
Corporate [Member]
                      
Segment Reporting Information [Line Items]                      
Assets $ 279.7       $ 533.6       $ 279.7 $ 533.6 $ 1,534.6
[1] Includes capital lease additions and non-cash accruals. Refer to NOTE 21 - CASH FLOW INFORMATION