Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 29, 2019		Jun. 30, 2018		Jun. 29, 2019		Jun. 30, 2018
Statement Of Comprehensive Income [Abstract]
Net earnings	$ 412,277		$ 713,615		$ 943,070		$ 1,093,727
Other comprehensive income:
Net unrealized loss on hedging derivatives, net of income taxes of $(1,700) and $(1,100) for the second quarter of 2019 and 2018, respectively, and $(1,500) and $(600) for the first six months of 2019 and 2018, respectively	(5,217)		(3,647)		(4,486)		(4,399)
Reclassification adjustment for settlement of hedging derivatives included in net income, net of income taxes of $200 and $100 for the second quarter of 2019 and 2018, respectively, and $0 and $100 for the first six months of 2019 and 2018, respectively	517	[1]	447	[2]	(114)	[1]	399	[2]
Foreign currency translation gain (loss), net of income taxes of $0 for the second quarter and first six months of 2019 and 2018	15,727		(43,466)		9,087		(37,351)
Net current-period other comprehensive income (loss)	11,027		(46,666)		4,487		(41,351)
Comprehensive income	423,304		666,949		947,557		1,052,376
Comprehensive income attributable to noncontrolling interests	(25,794)		(30,462)		(54,781)		(56,395)
Comprehensive income attributable to Nucor stockholders	$ 397,510		$ 636,487		$ 892,776		$ 995,981

[1] Includes $517 and $(114) of accumulated other comprehensive income (loss) reclassifications into cost of products sold for net losses on commodity contracts in the second quarter and first six months of 2019, respectively. The tax impacts of those reclassifications were $200 and $0 in the second quarter and first six months of 2019, respectively.

[2] Includes $447 and $399 of accumulated other comprehensive income (loss) reclassifications into cost of products sold for net losses on commodity contracts in the second quarter and first six months of 2018, respectively. The tax impacts of those reclassifications were $100 in both the second quarter and first six months of 2018.