Document and Entity Information	6 Months Ended
	Jun. 29, 2019 shares
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 29, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	NUE
Entity Registrant Name	NUCOR CORP
Entity Central Index Key	0000073309
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	1-4119
Entity Tax Identification Number	131860817
Entity Address, Address Line One	1915 Rexford Road
Entity Address, City or Town	Charlotte
Entity Address, State or Province	North Carolina
Entity Address, Postal Zip Code	28211
City Area Code	704
Local Phone Number	366-7000
Entity Common Stock, Shares Outstanding	303,157,475