Stockholders' Equity (Schedule Of Changes In Stockholders' Equity) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			$ 7,706,580	$ 7,330,694
Total comprehensive income	201,557	118,082	522,298	708,985
Stock options			20,052	16,224
Issuance of stock under award plans, net of forfeitures			31,292	24,117
Amortization of unearned compensation			600	1,300
Dividends declared			(350,041)	(346,284)
Distributions to noncontrolling interests			(66,562)	(55,855)
Other			(645)
Stockholders' equity, end of period	7,863,574	7,679,181	7,863,574	7,679,181
Attributable to Nucor Corporation [Member]
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			7,474,885	7,120,070
Total comprehensive income			457,201	647,309
Stock options			20,052	16,224
Issuance of stock under award plans, net of forfeitures			31,292	24,117
Amortization of unearned compensation			600	1,300
Dividends declared			(350,041)	(346,284)
Distributions to noncontrolling interests
Other			(645)
Stockholders' equity, end of period	7,633,344	7,462,736	7,633,344	7,462,736
Attributable to Noncontrolling Interests [Member]
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			231,695	210,624
Total comprehensive income			65,097	61,676
Stock options
Issuance of stock under award plans, net of forfeitures
Amortization of unearned compensation
Dividends declared
Distributions to noncontrolling interests			(66,562)	(55,855)
Other
Stockholders' equity, end of period	$ 230,230	$ 216,445	$ 230,230	$ 216,445