Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) [Member]	Treasury Stock (at cost) [Member]	Total Nucor Stockholders' Equity [Member]	Noncontrolling Interests [Member]
BALANCES, beginning of period at Dec. 31, 2016	$ 8,254,708	$ 151,734	$ 1,974,672	$ 7,630,916	$ (317,843)	$ (1,559,614)	$ 7,879,865	$ 374,843
BALANCES, shares at beginning of period at Dec. 31, 2016		379,334				60,597
Net earnings	1,380,571			1,318,688			1,318,688	61,883
Other comprehensive income (loss)	63,162				63,162		63,162
Stock options exercised	$ 7,069	$ 73	6,996				7,069
Stock options exercised (in shares)	183	183
Stock option expense	$ 8,233		8,233				8,233
Issuance of stock under award plans, net of forfeitures	37,018	$ 153	30,238			$ 6,627	37,018
Issuance of stock under award plans, net of forfeitures, shares		383				(257)
Amortization of unearned compensation	1,200		1,200				1,200
Treasury stock value acquired	(90,304)					$ (90,304)	(90,304)
Treasury stock shares acquired						1,591
Cash dividends declared	(485,895)			(485,895)			(485,895)
Distributions to noncontrolling interests	(90,974)							(90,974)
BALANCES, end of period at Dec. 31, 2017	9,084,788	$ 151,960	2,021,339	8,463,709	(254,681)	$ (1,643,291)	8,739,036	345,752
BALANCES, shares at end of period at Dec. 31, 2017		379,900				61,931
Net earnings	2,481,084			2,360,767			2,360,767	120,317
Other comprehensive income (loss)	(49,452)				(49,452)		(49,452)
Stock options exercised	$ 24,102	$ 84	14,675			$ 9,343	24,102
Stock options exercised (in shares)	543	210				(333)
Stock option expense	$ 4,563		4,563				4,563
Issuance of stock under award plans, net of forfeitures	52,313	$ 17	31,361			$ 20,935	52,313
Issuance of stock under award plans, net of forfeitures, shares		44				(762)
Amortization of unearned compensation	1,777		1,777				1,777
Treasury stock value acquired	(853,997)					$ (853,997)	(853,997)
Treasury stock shares acquired						13,726
Cash dividends declared	(487,031)			(487,031)			(487,031)
Distributions to noncontrolling interests	(56,179)							(56,179)
BALANCES, end of period at Dec. 31, 2018	10,201,968	$ 152,061	2,073,715	10,337,445	(304,133)	$ (2,467,010)	9,792,078	409,890
BALANCES, shares at end of period at Dec. 31, 2018		380,154				74,562
Net earnings	1,370,910			1,271,143			1,271,143	99,767
Other comprehensive income (loss)	(718)				(718)		(718)
Stock options exercised	$ 16,146		1,624			$ 14,522	16,146
Stock options exercised (in shares)	425					(425)
Stock option expense	$ 4,662		4,662				4,662
Issuance of stock under award plans, net of forfeitures	62,735		25,637			$ 37,098	62,735
Issuance of stock under award plans, net of forfeitures, shares						(1,095)
Amortization of unearned compensation	2,008		2,008				2,008
Treasury stock value acquired	(298,541)					$ (298,541)	(298,541)
Treasury stock shares acquired						5,300
Cash dividends declared	(491,647)			(491,647)			(491,647)
Distributions to noncontrolling interests	(76,347)							(76,347)
Other				(1,885)	1,885
BALANCES, end of period at Dec. 31, 2019	$ 10,791,176	$ 152,061	$ 2,107,646	$ 11,115,056	$ (302,966)	$ (2,713,931)	$ 10,357,866	$ 433,310
BALANCES, shares at end of period at Dec. 31, 2019		380,154				78,342