Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016
Statement Of Comprehensive Income [Abstract]
Net earnings	$ 341,724	$ 271,369	$ 719,372	$ 393,866
Other comprehensive income:
Net unrealized (loss) income on hedging derivatives, net of income taxes of $0 and $1,900 for the second quarter of 2017 and 2016, respectively, and ($1,000) and $900 for the first six months of 2017 and 2016, respectively	(71)	3,243	(1,706)	1,512
Reclassification adjustment for loss on settlement of hedging derivatives included in net income, net of income taxes of $0 and $1,900 for the second quarter of 2017 and 2016, respectively, and $300 and $3,600 for the first six months of 2017 and 2016, respectively	171	3,257	656	6,288
Foreign currency translation gain, net of income taxes of $0 for the second quarter of 2017 and 2016, and $0 for the first six months of 2017 and 2016	23,957	8,287	25,958	62,184
Net current-period other comprehensive income (loss)	24,057	14,787	24,908	69,984
Comprehensive income	365,781	286,156	744,280	463,850
Comprehensive income attributable to noncontrolling interests	(18,676)	(27,749)	(39,425)	(62,681)
Comprehensive income attributable to Nucor stockholders	$ 347,105	$ 258,407	$ 704,855	$ 401,169