Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2015	Jul. 05, 2014	Jul. 04, 2015	Jul. 05, 2014
Income Statement [Abstract]
Net sales	$ 4,357,609	$ 5,291,075	$ 8,757,049	$ 10,399,519
Costs, expenses and other:
Cost of products sold	3,971,303	4,875,208	8,082,461	9,606,450
Marketing, administrative and other expenses	128,592	132,813	253,153	266,247
Equity in earnings of unconsolidated affiliates	(694)	(3,202)	(435)	(7,676)
Interest expense, net	42,186	44,391	86,603	85,132
Costs, expenses and other, total	4,141,387	5,049,210	8,421,782	9,950,153
Earnings before income taxes and noncontrolling interests	216,222	241,865	335,267	449,366
Provision for income taxes	56,878	74,930	91,631	152,735
Net earnings	159,344	166,935	243,636	296,631
Earnings attributable to noncontrolling interests	34,589	19,894	51,081	38,559
Net earnings attributable to Nucor stockholders	$ 124,755	$ 147,041	$ 192,555	$ 258,072
Net earnings per share:
Basic	$ 0.39	$ 0.46	$ 0.60	$ 0.80
Diluted	$ 0.39	$ 0.46	$ 0.60	$ 0.80
Average shares outstanding:
Basic	320,506	319,693	320,409	319,597
Diluted	320,708	319,981	320,594	319,872
Dividends declared per share	$ 0.3725	$ 0.3700	$ 0.7450	$ 0.7400