Stockholders' Equity - Schedule of Change in Stockholder's Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			$ 9,084,788	$ 8,254,708
Total comprehensive income	$ 666,949	$ 365,781	1,052,376	744,280
Stock options			16,218	11,068
Issuance of stock under award plans, net of forfeitures			34,706	23,593
Amortization of unearned compensation			1,000	700
Treasury stock acquired			(170,315)
Dividends declared			(243,219)	(243,016)
Distributions to noncontrolling interests			(40,130)	(79,420)
Stockholders' equity, end of period	9,735,424	8,711,913	9,735,424	8,711,913
Total Nucor Stockholders' Equity [Member]
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			8,739,036	7,879,865
Total comprehensive income			995,981	704,855
Stock options			16,218	11,068
Issuance of stock under award plans, net of forfeitures			34,706	23,593
Amortization of unearned compensation			1,000	700
Treasury stock acquired			(170,315)
Dividends declared			(243,219)	(243,016)
Stockholders' equity, end of period	9,373,407	8,377,065	9,373,407	8,377,065
Noncontrolling Interests [Member]
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			345,752	374,843
Total comprehensive income			56,395	39,425
Distributions to noncontrolling interests			(40,130)	(79,420)
Stockholders' equity, end of period	$ 362,017	$ 334,848	$ 362,017	$ 334,848