Condensed Consolidated Statements of Earnings (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 05, 2014	Jun. 29, 2013	Jul. 05, 2014	Jun. 29, 2013
Income Statement [Abstract]
Net sales	$ 5,291,075	$ 4,665,588	$ 10,399,519	$ 9,216,360
Costs, expenses and other:
Cost of products sold	4,875,208	4,352,463	9,606,450	8,600,019
Marketing, administrative and other expenses	132,813	123,150	266,247	239,375
Equity in earnings of unconsolidated affiliates	(3,202)	(1,585)	(7,676)	(413)
Interest expense, net	44,391	39,228	85,132	71,719
Costs, expenses and other, total	5,049,210	4,513,256	9,950,153	8,910,700
Earnings before income taxes and noncontrolling interests	241,865	152,332	449,366	305,660
Provision for income taxes	74,930	46,062	152,735	88,662
Net earnings	166,935	106,270	296,631	216,998
Earnings attributable to noncontrolling interests	19,894	21,125	38,559	47,064
Net earnings attributable to Nucor stockholders	$ 147,041	$ 85,145	$ 258,072	$ 169,934
Net earnings per share:
Basic	$ 0.46	$ 0.27	$ 0.80	$ 0.53
Diluted	$ 0.46	$ 0.27	$ 0.80	$ 0.53
Average shares outstanding:
Basic	319,693	318,903	319,597	318,796
Diluted	319,981	319,023	319,872	318,934
Dividends declared per share	$ 0.3700	$ 0.3675	$ 0.7400	$ 0.7350