Stockholders' Equity - Schedule of Change in Stockholder's Equity (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 02, 2021	Oct. 03, 2020	Oct. 02, 2021	Oct. 03, 2020
BALANCES, beginning of period	$ 12,709,651	$ 10,623,485	$ 11,231,861	$ 10,791,176
Net earnings	2,223,265	222,630	4,782,238	410,162
Other comprehensive income (loss)	(12,172)	25,367	32,960	(12,503)
Stock options exercised	15,075		$ 143,874
Stock options exercised (in shares)			2,839
Stock option expense	458	263	$ 3,367	2,402
Issuance of stock under award plans, net of forfeitures	11,629	11,189	8,893	38,996
Amortization of unearned compensation	400	400	1,200	1,300
Treasury stock value acquired	(857,703)		(1,773,848)	(39,499)
Cash dividends declared	(116,888)	(123,039)	(359,634)	(368,774)
Distributions to noncontrolling interests	(23,423)	(43,228)	(120,619)	(106,193)
BALANCES, end of period	13,950,292	10,717,067	13,950,292	10,717,067
Common Stock [Member]
BALANCES, beginning of period	$ 152,061	$ 152,061	$ 152,061	$ 152,061
BALANCES, shares at beginning of period	380,154	380,154	380,154	380,154
BALANCES, end of period	$ 152,061	$ 152,061	$ 152,061	$ 152,061
BALANCES, shares at end of period	380,154	380,154	380,154	380,154
Additional Paid-in Capital [Member]
BALANCES, beginning of period	$ 2,117,155	$ 2,106,907	$ 2,121,288	$ 2,107,646
Stock options exercised	2,699		38,523
Stock option expense	458	263	3,367	2,402
Issuance of stock under award plans, net of forfeitures	10,802	10,012	(32,864)	6,234
Amortization of unearned compensation	400	400	1,200	1,300
BALANCES, end of period	2,131,514	2,117,582	2,131,514	2,117,582
Retained Earnings [Member]
BALANCES, beginning of period	13,550,406	10,998,533	11,343,852	11,115,056
Net earnings	2,127,743	193,415	4,577,043	322,627
Cash dividends declared	(116,888)	(123,039)	(359,634)	(368,774)
Other		(1)		(1)
BALANCES, end of period	15,561,261	11,068,908	15,561,261	11,068,908
Accumulated Other Comprehensive Income (Loss) [Member]
BALANCES, beginning of period	(73,729)	(340,836)	(118,861)	(302,966)
Other comprehensive income (loss)	(12,172)	25,367	32,960	(12,503)
BALANCES, end of period	(85,901)	(315,469)	(85,901)	(315,469)
Treasury Stock (at cost) [Member]
BALANCES, beginning of period	$ (3,491,915)	$ (2,721,845)	$ (2,709,675)	$ (2,713,931)
BALANCES, shares at beginning of period	86,459	78,259	77,909	78,342
Stock options exercised	$ 12,376		$ 105,351
Stock options exercised (in shares)	(285)		(2,839)
Issuance of stock under award plans, net of forfeitures	$ 827	$ 1,177	$ 41,757	$ 32,762
Issuance of stock under award plans, net of forfeitures, shares	(19)	(34)	(1,060)	(942)
Treasury stock value acquired	$ (857,703)		$ (1,773,848)	$ (39,499)
Treasury stock acquired (in shares)	8,200		20,345	825
BALANCES, end of period	$ (4,336,415)	$ (2,720,668)	$ (4,336,415)	$ (2,720,668)
BALANCES, shares at end of period	94,355	78,225	94,355	78,225
Total Nucor Stockholders' Equity [Member]
BALANCES, beginning of period	$ 12,253,978	$ 10,194,820	$ 10,788,665	$ 10,357,866
Net earnings	2,127,743	193,415	4,577,043	322,627
Other comprehensive income (loss)	(12,172)	25,367	32,960	(12,503)
Stock options exercised	15,075		143,874
Stock option expense	458	263	3,367	2,402
Issuance of stock under award plans, net of forfeitures	11,629	11,189	8,893	38,996
Amortization of unearned compensation	400	400	1,200	1,300
Treasury stock value acquired	(857,703)		(1,773,848)	(39,499)
Cash dividends declared	(116,888)	(123,039)	(359,634)	(368,774)
Other		(1)		(1)
BALANCES, end of period	13,422,520	10,302,414	13,422,520	10,302,414
Noncontrolling Interests [Member]
BALANCES, beginning of period	455,673	428,665	443,196	433,310
Net earnings	95,522	29,215	205,195	87,535
Distributions to noncontrolling interests	(23,423)	(43,228)	(120,619)	(106,193)
Other		1		1
BALANCES, end of period	$ 527,772	$ 414,653	$ 527,772	$ 414,653