Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2016	Jul. 04, 2015	Jul. 02, 2016	Jul. 04, 2015
Statement Of Comprehensive Income [Abstract]
Net earnings	$ 258,336	$ 159,344	$ 362,797	$ 243,636
Other comprehensive income (loss):
Net unrealized income (loss) on hedging derivatives, net of income taxes of $1,900 and ($300) for the second quarter of 2016 and 2015, respectively, and $900 and ($1,600) for the first six months of 2016 and 2015, respectively	3,243	(464)	1,512	(2,732)
Reclassification adjustment for loss on settlement of hedging derivatives included in net income, net of income taxes of $1,900 and $700 for the second quarter of 2016 and 2015, respectively, and $3,600 and $800 for the first six months of 2016 and 2015, respectively	3,257	1,164	6,288	1,332
Foreign currency translation gain (loss), net of income taxes of $0 for the second quarter of 2016 and 2015, and $0 for the first six months of 2016 and 2015	8,287	24,395	62,184	(92,300)
Other, net of income taxes of $1,500 for the second quarter and first six months of 2015.		2,700		2,700
Net current-period other comprehensive income (loss)	14,787	27,795	69,984	(91,000)
Comprehensive income	273,123	187,139	432,781	152,636
Comprehensive income attributable to noncontrolling interests	(24,564)	(34,589)	(58,271)	(51,081)
Comprehensive income attributable to Nucor stockholders	$ 248,559	$ 152,550	$ 374,510	$ 101,555