Stock-Based Compensation - Summary of Nucor's Restricted Stock Unit ("RSU") Activity (Detail) - Restricted Stock Units [Member] shares in Thousands	3 Months Ended
	Apr. 05, 2025 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested at beginning of year, Shares | shares	1,021
Vested, Shares | shares	(53)
Canceled, Shares | shares	(7)
Unvested at April 5, 2025, Shares | shares	961
Unvested at beginning of year, Grant Date Fair Value Per Share | $ / shares	$ 144.89
Vested, Grant Date Fair Value Per Share | $ / shares	119.94
Canceled, Grant Date Fair Value Per Share | $ / shares	149.12
Unvested at April 5, 2025, Grant Date Fair Value Per Share | $ / shares	$ 146.23