Document and Entity Information	6 Months Ended
	Jul. 05, 2014
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jul. 05, 2014
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q2
Entity Registrant Name	NUCOR CORP
Entity Central Index Key	0000073309
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	318,843,007