Condensed Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2020	Jun. 29, 2019	Jul. 04, 2020	Jun. 29, 2019
Income Statement [Abstract]
Net sales	$ 4,327,306	$ 5,895,986	$ 9,951,643	$ 11,992,610
Costs, expenses and other:
Cost of products sold	3,949,347	5,120,492	8,944,416	10,321,224
Marketing, administrative and other expenses	142,017	208,980	295,409	389,719
Equity in losses (earnings) of unconsolidated affiliates	14,078	(1,138)	14,901	(4,044)
Losses on assets	5,000		292,846
Interest expense, net	35,807	33,030	76,717	61,473
Costs, expenses and other, total	4,146,249	5,361,364	9,624,289	10,768,372
Earnings before income taxes and noncontrolling interests	181,057	534,622	327,354	1,224,238
Provision for income taxes	47,904	122,345	139,822	281,168
Net earnings	133,153	412,277	187,532	943,070
Earnings attributable to noncontrolling interests	24,272	25,794	58,320	54,781
Net earnings attributable to Nucor stockholders	$ 108,881	$ 386,483	$ 129,212	$ 888,289
Net earnings per share:
Basic	$ 0.36	$ 1.26	$ 0.42	$ 2.89
Diluted	$ 0.36	$ 1.26	$ 0.42	$ 2.88
Average shares outstanding:
Basic	302,921	305,461	302,915	306,017
Diluted	302,933	305,952	302,932	306,559