星空传媒 Inc. Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

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

Segment Reporting (Summary Of Assets By Segment) (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]	听	听
Total assets	$ 15,296.8	$ 14,541.7
U.S. Iron Ore [Member]	听	听
Segment Reporting Information [Line Items]	听	听
Total assets	1,841.4	1,691.8
Eastern Canadian Iron Ore [Member]	听	听
Segment Reporting Information [Line Items]	听	听
Total assets	8,307.7	7,973.1
Asia Pacific Iron Ore [Member]	听	听
Segment Reporting Information [Line Items]	听	听
Total assets	1,864.8	1,511.2
North American Coal [Member]	听	听
Segment Reporting Information [Line Items]	听	听
Total assets	1,904.6	1,814.4
All Other Segments [Member]	听	听
Segment Reporting Information [Line Items]	听	听
Total assets	960.2	1,017.6
Total Segment Assets [Member]	听	听
Segment Reporting Information [Line Items]	听	听
Total assets	14,878.7	14,008.1
Corporate [Member]	听	听
Segment Reporting Information [Line Items]	听	听
Total assets	$ 418.1	$ 533.6

- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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