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	3 Months Ended
	Apr. 01, 2017 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested at beginning of year, Shares	67
Granted, Shares	172
Vested, Shares	(144)
Canceled, Shares	0
Unvested at end of year, Shares	95
Shares reserved for future grants	683
Unvested at beginning of year, Grant Date Fair Value | $ / shares	$ 45.77
Granted, Grant Date Fair Value | $ / shares	60.62
Vested, Grant Date Fair Value | $ / shares	51.69
Canceled, Grant Date Fair Value | $ / shares	0
Unvested at end of year, Grant Date Fair Value | $ / shares	$ 54.45