Stock-Based Compensation - Summary of Nucor's Restricted Stock Activity under AIP and LTIP (Detail) - Restricted Stock And Restricted Stock Units [Member] - AIP and LTIP [Member] shares in Thousands	9 Months Ended
	Oct. 03, 2015 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested at beginning of year, Shares	65
Granted, Shares	136
Vested, Shares	(134)
Canceled, Shares	0
Unvested at end of period, Shares	67
Shares reserved for future grants	975
Unvested at beginning of year, Grant Date Fair Value | $ / shares	$ 48.20
Granted, Grant Date Fair Value | $ / shares	47.07
Vested, Grant Date Fair Value | $ / shares	47.11
Canceled, Grant Date Fair Value | $ / shares	0
Unvested at end of period, Grant Date Fair Value | $ / shares	$ 48.08