ÐÇ¿Õ´«Ã½

Quarterly report pursuant to Section 13 or 15(d)

Segment Reporting (Summary Of Assets By Segment) (Detail)

v2.4.0.6
Segment Reporting (Summary Of Assets By Segment) (Detail) (USD $)
In Millions, unless otherwise specified
Jun. 30, 2012
Dec. 31, 2011
Segment Reporting Information [Line Items] Ìý Ìý
Total assets $ 15,194.3 $ 14,541.7
U.S. Iron Ore [Member]
Ìý Ìý
Segment Reporting Information [Line Items] Ìý Ìý
Total assets 1,915.4 1,691.8
Eastern Canadian Iron Ore [Member]
Ìý Ìý
Segment Reporting Information [Line Items] Ìý Ìý
Total assets 8,138.3 7,973.1
North American Coal [Member]
Ìý Ìý
Segment Reporting Information [Line Items] Ìý Ìý
Total assets 1,908.2 1,814.4
Asia Pacific Iron Ore [Member]
Ìý Ìý
Segment Reporting Information [Line Items] Ìý Ìý
Total assets 1,859.4 1,511.2
Other Segment [Member]
Ìý Ìý
Segment Reporting Information [Line Items] Ìý Ìý
Total assets 1,045.2 1,017.6
Total Segment Assets [Member]
Ìý Ìý
Segment Reporting Information [Line Items] Ìý Ìý
Total assets 14,866.5 14,008.1
Corporate [Member]
Ìý Ìý
Segment Reporting Information [Line Items] Ìý Ìý
Total assets $ 327.8 $ 533.6