Nature Of Operations And Basis Of Presentation (Narrative) (Details) (Nucor-Yamato Steel Company [Member])	Dec. 31, 2011
Nucor-Yamato Steel Company [Member]
Percentage of equity interest	51.00%

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant