Stockholders' Equity (Schedule Of Changes In Stockholders' Equity) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Apr. 02, 2011
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period	$ 7,706,580	$ 7,330,694
Total comprehensive income	226,054	253,222
Stock options	6,189	3,040
Issuance of stock under award plans, net of forfeitures	13,506	11,156
Amortization of unearned compensation	300	500
Dividends declared	(116,441)	(115,327)
Distributions to noncontrolling interests	(39,857)	(29,694)
Other	(629)
Stockholders' equity, end of period	7,795,702	7,453,591
Nucor-Yamato Steel Company [Member]
Stockholders' Equity [Line Items]
Noncontrolling interest, ownership percentage by parent	51.00%
Barker Steel Company, Inc. [Member]
Stockholders' Equity [Line Items]
Noncontrolling interest, ownership percentage by parent	90.00%
Attributable To Nucor Corporation [Member]
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period	7,474,885	7,120,070
Total comprehensive income	207,774	231,935
Stock options	6,189	3,040
Issuance of stock under award plans, net of forfeitures	13,506	11,156
Amortization of unearned compensation	300	500
Dividends declared	(116,441)	(115,327)
Other	(629)
Stockholders' equity, end of period	7,585,584	7,251,374
Attributable To Noncontrolling Interests [Member]
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period	231,695	210,624
Total comprehensive income	18,280	21,287
Distributions to noncontrolling interests	(39,857)	(29,694)
Stockholders' equity, end of period	$ 210,118	$ 202,217