Basis of Interim Presentation - Schedule of Adjustments to Condensed Consolidated Statement of Earnings (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of products sold	$ 4,465,144	$ 3,660,512	$ 8,520,073	$ 7,061,103
Provision for income taxes	166,412	118,515	337,739	165,581
Net earnings	341,724	271,369	719,372	393,866
Earnings attributable to noncontrolling interests	18,676	27,749	39,425	62,681
Net earnings attributable to Nucor stockholders	323,048	243,620	679,947	331,185
Net earnings per share:
Cost of products sold	4,465,144	3,660,512	8,520,073	7,061,103
Provision for income taxes	166,412	118,515	337,739	165,581
Net earnings	341,724	271,369	719,372	393,866
Earnings attributable to noncontrolling interests	18,676	27,749	39,425	62,681
Net earnings attributable to Nucor stockholders	$ 323,048	$ 243,620	$ 679,947	$ 331,185
Basic	$ 1.00	$ 0.76	$ 2.12	$ 1.03
Diluted	$ 1.00	$ 0.76	$ 2.11	$ 1.03
As Originally Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of products sold		$ 3,679,512		$ 7,108,140
Provision for income taxes		112,548		149,613
Net earnings		258,336		362,797
Earnings attributable to noncontrolling interests		24,564		58,271
Net earnings attributable to Nucor stockholders		233,772		304,526
Net earnings per share:
Cost of products sold		3,679,512		7,108,140
Provision for income taxes		112,548		149,613
Net earnings		258,336		362,797
Earnings attributable to noncontrolling interests		24,564		58,271
Net earnings attributable to Nucor stockholders		$ 233,772		$ 304,526
Basic		$ 0.73		$ 0.95
Diluted		$ 0.73		$ 0.95
Effect of Change [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of products sold		$ (19,000)		$ (47,037)
Provision for income taxes		5,967		15,968
Net earnings		13,033		31,069
Earnings attributable to noncontrolling interests		3,185		4,410
Net earnings attributable to Nucor stockholders		9,848		26,659
Net earnings per share:
Cost of products sold		(19,000)		(47,037)
Provision for income taxes		5,967		15,968
Net earnings		13,033		31,069
Earnings attributable to noncontrolling interests		3,185		4,410
Net earnings attributable to Nucor stockholders		$ 9,848		$ 26,659
Basic		$ 0.03		$ 0.08
Diluted		$ 0.03		$ 0.08