Condensed Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 04, 2020	Mar. 30, 2019
Income Statement [Abstract]
Net sales	$ 5,624,337	$ 6,096,624
Costs, expenses and other:
Cost of products sold	4,995,069	5,200,732
Marketing, administrative and other expenses	153,392	180,739
Equity in losses (earnings) of unconsolidated affiliates	823	(2,906)
Losses on assets	287,846
Interest expense, net	40,910	28,443
Costs, expenses and other, total	5,478,040	5,407,008
Earnings before income taxes and noncontrolling interests	146,297	689,616
Provision for income taxes	91,918	158,823
Net earnings	54,379	530,793
Earnings attributable to noncontrolling interests	34,048	28,987
Net earnings attributable to Nucor stockholders	$ 20,331	$ 501,806
Net earnings per share:
Basic	$ 0.07	$ 1.63
Diluted	$ 0.07	$ 1.63
Average shares outstanding:
Basic	302,909	306,585
Diluted	302,932	307,180