Stockholders' Equity - Schedule of Change in Stockholder's Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			$ 8,254,708	$ 7,849,877
Total comprehensive income	$ 341,184	$ 324,159	1,085,464	788,009
Stock options			13,300	13,229
Issuance of stock under award plans, net of forfeitures			30,787	25,929
Amortization of unearned compensation			1,000	600
Treasury stock acquired			(90,305)	(5,173)
Dividends declared			(364,046)	(360,955)
Distributions to noncontrolling interests			(85,094)	(86,808)
Other				(2,378)
Stockholders' equity, end of period	8,845,814	8,222,330	8,845,814	8,222,330
Total Nucor Stockholders' Equity [Member]
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			7,879,865	7,477,816
Total comprehensive income			1,034,784	699,410
Stock options			13,300	13,229
Issuance of stock under award plans, net of forfeitures			30,787	25,929
Amortization of unearned compensation			1,000	600
Treasury stock acquired			(90,305)	(5,173)
Dividends declared			(364,046)	(360,955)
Other				(602)
Stockholders' equity, end of period	8,505,385	7,850,254	8,505,385	7,850,254
Noncontrolling Interests [Member]
Stockholders' Equity [Line Items]
Stockholders' equity, beginning of period			374,843	372,061
Total comprehensive income			50,680	88,599
Distributions to noncontrolling interests			(85,094)	(86,808)
Other				(1,776)
Stockholders' equity, end of period	$ 340,429	$ 372,076	$ 340,429	$ 372,076