Debt - Additional Information (Detail) (Nucor-Yamato Steel Company [Member], USD $) In Millions, unless otherwise specified	Jun. 29, 2013	Jun. 30, 2012
Intercompany Debt Instruments [Line Items]
Note payable principal amount	$ 100.0
Ownership percentage	51.00%	51.00%
Notes Payable [Member]
Intercompany Debt Instruments [Line Items]
Interest rate of notes payable issued to NYS	0.09%

The amount for notes payable (written promise to pay), due to related parties.

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

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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Balance Type:	credit
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