Condensed Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2016	Jul. 04, 2015	Jul. 02, 2016	Jul. 04, 2015
Income Statement [Abstract]
Net sales	$ 4,245,772	$ 4,357,609	$ 7,961,348	$ 8,757,049
Costs, expenses and other:
Cost of products sold	3,679,512	3,971,303	7,108,140	8,082,461
Marketing, administrative and other expenses	161,711	128,592	271,456	253,153
Equity in earnings of unconsolidated affiliates	(6,819)	(694)	(16,064)	(435)
Interest expense, net	40,484	42,186	85,406	86,603
Costs, expenses and other, total	3,874,888	4,141,387	7,448,938	8,421,782
Earnings before income taxes and noncontrolling interests	370,884	216,222	512,410	335,267
Provision for income taxes	112,548	56,878	149,613	91,631
Net earnings	258,336	159,344	362,797	243,636
Earnings attributable to noncontrolling interests	24,564	34,589	58,271	51,081
Net earnings attributable to Nucor stockholders	$ 233,772	$ 124,755	$ 304,526	$ 192,555
Net earnings per share:
Basic	$ 0.73	$ 0.39	$ 0.95	$ 0.60
Diluted	$ 0.73	$ 0.39	$ 0.95	$ 0.60
Average shares outstanding:
Basic	319,360	320,506	319,299	320,409
Diluted	319,578	320,708	319,435	320,594
Dividends declared per share	$ 0.3750	$ 0.3725	$ 0.7500	$ 0.7450