Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2015	Jul. 05, 2014	Jul. 04, 2015	Jul. 05, 2014
Statement Of Comprehensive Income [Abstract]
Net earnings	$ 159,344	$ 166,935	$ 243,636	$ 296,631
Other comprehensive income (loss):
Net unrealized (loss) income on hedging derivatives, net of income taxes of ($300) and $100 for the second quarter of 2015 and 2014, respectively, and ($1,600) and ($1,000) for the first six months of 2015 and 2014, respectively	(464)	238	(2,732)	(1,633)
Reclassification adjustment for loss (income) on settlement of hedging derivatives included in net income, net of income taxes of $700 and ($100) for the second quarter of 2015 and 2014, respectively, and $800 and $100 for the first six months of 2015 and 2014, respectively	1,164	(238)	1,332	233
Foreign currency translation gain (loss), net of income taxes of $0 for the second quarter of 2015 and 2014, and $0 and ($400) for the first six months of 2015 and 2014, respectively	24,395	31,845	(92,300)	(11,632)
Other, net of income taxes of $1,500 and $0 for the second quarter of 2015 and 2014, respectively, and $1,500 and $0 for the first six months of 2015 and 2014, respectively	2,700		2,700
Net current-period other comprehensive income (loss)	27,795	31,845	(91,000)	(13,032)
Comprehensive income	187,139	198,780	152,636	283,599
Comprehensive income attributable to noncontrolling interests	(34,589)	(19,894)	(51,081)	(38,559)
Comprehensive income attributable to Nucor stockholders	$ 152,550	$ 178,886	$ 101,555	$ 245,040