Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Statement Of Comprehensive Income [Abstract]
Net earnings	$ 266,105	$ 331,365	$ 985,477	$ 725,231
Other comprehensive income (loss):
Net unrealized income (loss) on hedging derivatives, net of income taxes of $300 and ($300) for the third quarter of 2017 and 2016, respectively, and ($700) and $600 for the first nine months of 2017 and 2016, respectively	405	(600)	(1,301)	912
Reclassification adjustment for loss on settlement of hedging derivatives included in net income, net of income taxes of $0 and $1,200 for the third quarter of 2017 and 2016, respectively, and $300 and $4,800 for the first nine months of 2017 and 2016, respectively	195	2,000	851	8,288
Foreign currency translation gain (loss), net of income taxes of $0 for the third quarter of 2017 and 2016, and $0 for the first nine months of 2017 and 2016	74,479	(8,606)	100,437	53,578
Net current-period other comprehensive income (loss)	75,079	(7,206)	99,987	62,778
Comprehensive income	341,184	324,159	1,085,464	788,009
Comprehensive income attributable to noncontrolling interests	(11,255)	(25,918)	(50,680)	(88,599)
Comprehensive income attributable to Nucor stockholders	$ 329,929	$ 298,241	$ 1,034,784	$ 699,410