Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 05, 2014	Jun. 29, 2013	Jul. 05, 2014	Jun. 29, 2013
Statement Of Comprehensive Income [Abstract]
Net earnings	$ 166,935	$ 106,270	$ 296,631	$ 216,998
Other comprehensive income (loss):
Net unrealized income (loss) on hedging derivatives, net of income taxes of $100 and $0 for the second quarter of 2014 and 2013, respectively, and $(1,000) and $0 for the first six months of 2014 and 2013, respectively	238		(1,633)
Reclassification adjustment for (income) loss on settlement of hedging derivatives included in net income, net of income taxes of $(100) and $0 for the second quarter of 2014 and 2013, respectively, and $100 and $0 for the first six months of 2014 and 2013, respectively	(238)		233
Foreign currency translation gain (loss), net of income taxes of $0 and ($200) for the second quarter of 2014 and 2013, respectively, and $(400) and ($200) for the first six months of 2014 and 2013, respectively	31,845	(15,582)	(11,632)	(66,095)
Net current-period other comprehensive income (loss)	31,845	(15,582)	(13,032)	(66,095)
Comprehensive income	198,780	90,688	283,599	150,903
Comprehensive income attributable to noncontrolling interests	(19,894)	(21,125)	(38,559)	(47,064)
Comprehensive income attributable to Nucor stockholders	$ 178,886	$ 69,563	$ 245,040	$ 103,839