Goodwill And Other Intangible Assets (Schedule Of Change In Net Carrying Amount Of Goodwill By Segment) (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2012	Jun. 30, 2012 Steel Mills [Member]	Jun. 30, 2012 Steel Products [Member]	Jun. 30, 2012 Raw Materials [Member]	Jun. 30, 2012 All Other [Member]	Dec. 31, 2011 All Other [Member]
Goodwill [Line Items]
Balance, beginning of period	$ 1,830,661	$ 268,466	$ 790,441	$ 682,902	$ 88,852	$ 88,852
Acquisitions	153,848	143,190		10,658
Translation	4,365		4,365
Balance, end of period	$ 1,988,874	$ 411,656	$ 794,806	$ 693,560	$ 88,852	$ 88,852

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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-Publisher FASB

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

- Definition

The aggregate amount of goodwill acquired in the period and allocated to the reportable segment. The value is stated at fair value based on the purchase price allocation.

+ References+ Details