Condensed Consolidated Statements of Earnings (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 04, 2014	Sep. 28, 2013	Oct. 04, 2014	Sep. 28, 2013
Income Statement [Abstract]
Net sales	$ 5,701,869	$ 4,940,936	$ 16,101,388	$ 14,157,296
Costs, expenses and other:
Cost of products sold	5,102,283	4,532,393	14,708,733	13,132,412
Marketing, administrative and other expenses	152,604	125,126	418,851	364,501
Equity in earnings of unconsolidated affiliates	(2,352)	(2,252)	(10,028)	(2,665)
Interest expense, net	45,349	37,467	130,481	109,186
Costs, expenses and other, total	5,297,884	4,692,734	15,248,037	13,603,434
Earnings before income taxes and noncontrolling interests	403,985	248,202	853,351	553,862
Provision for income taxes	129,784	70,087	282,519	158,749
Net earnings	274,201	178,115	570,832	395,113
Earnings attributable to noncontrolling interests	28,754	30,518	67,313	77,582
Net earnings attributable to Nucor stockholders	$ 245,447	$ 147,597	$ 503,519	$ 317,531
Net earnings per share:
Basic	$ 0.76	$ 0.46	$ 1.57	$ 0.99
Diluted	$ 0.76	$ 0.46	$ 1.57	$ 0.99
Average shares outstanding:
Basic	320,023	319,341	319,737	318,979
Diluted	320,337	319,526	320,025	319,132
Dividends declared per share	$ 0.3700	$ 0.3675	$ 1.1100	$ 1.1025