Quarterly report pursuant to Section 13 or 15(d)

Segment Reporting (Schedule Of Segment Reporting Information, By Segment) (Detail)

v2.4.0.6
Segment Reporting (Schedule Of Segment Reporting Information, By Segment) (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Segment Reporting Information [Line Items]        
Revenues from product sales and services $ 1,626.0 $ 1,805.8 $ 2,890.7 $ 2,989.0
Sales margin 449.3 731.6 752.8 1,331.1
Other operating expense (84.0) (113.8) (156.4) (171.2)
Depreciation, depletion and amortization 132.1 106.8 249.4 186.6
Other income (expense) (47.6) (28.0) (91.1) (7.1)
Capital additions 266.1 [1] 206.4 [1] 619.5 [1] 297.4 [1]
Income from continuing operations before income taxes and equity loss from ventures 317.7 589.8 505.3 1,152.8
Revenues from product sales and services for reportable segments, percent 100.00% 100.00% 100.00% 100.00%
U.S. Iron Ore [Member]
       
Segment Reporting Information [Line Items]        
Revenues from product sales and services 705.0 885.2 1,146.7 1,395.3
Sales margin 286.1 441.1 452.9 802.4
Depreciation, depletion and amortization 23.8 22.2 47.0 39.5
Capital additions 28.1 [1] 55.7 [1] 62.9 [1] 87.3 [1]
Revenues from product sales and services for reportable segments, percent 43.00% 49.00% 40.00% 47.00%
Eastern Canadian Iron Ore [Member]
       
Segment Reporting Information [Line Items]        
Revenues from product sales and services 303.9 297.6 524.6 424.9
Sales margin 11.7 68.0 (2.6) 102.5
Depreciation, depletion and amortization 38.6 31.5 76.5 41.3
Capital additions 177.3 [1] 60.7 [1] 307.9 [1] 64.2 [1]
Revenues from product sales and services for reportable segments, percent 19.00% 16.00% 18.00% 14.00%
North American Coal [Member]
       
Segment Reporting Information [Line Items]        
Revenues from product sales and services 209.2 159.7 399.2 324.7
Sales margin (9.6) (14.8) 5.0 (17.7)
Depreciation, depletion and amortization 24.3 20.8 44.4 42.4
Capital additions 32.7 [1] 28.5 [1] 71.8 [1] 56.0 [1]
Revenues from product sales and services for reportable segments, percent 13.00% 9.00% 14.00% 11.00%
Asia Pacific Iron Ore [Member]
       
Segment Reporting Information [Line Items]        
Revenues from product sales and services 361.3 381.6 721.1 727.0
Sales margin 146.8 205.0 271.9 400.8
Depreciation, depletion and amortization 39.8 24.9 69.8 48.9
Capital additions 16.9 [1] 58.0 [1] 126.2 [1] 83.3 [1]
Revenues from product sales and services for reportable segments, percent 22.00% 21.00% 25.00% 24.00%
Other Segment [Member]
       
Segment Reporting Information [Line Items]        
Revenues from product sales and services 46.6 81.7 99.1 117.1
Sales margin 14.3 32.3 25.6 43.1
Depreciation, depletion and amortization 5.6 7.4 11.7 14.5
Capital additions $ 11.1 [1] $ 3.5 [1] $ 50.7 [1] $ 6.6 [1]
Revenues from product sales and services for reportable segments, percent 3.00% 5.00% 3.00% 4.00%
[1] Includes capital lease additions and non-cash accruals. Refer to NOTE 20 - CASH FLOW INFORMATION