Stock-Based Compensation - Summary of Nucor's Restricted Stock Unit ("RSU") Activity (Detail) - Restricted Stock Units [Member] shares in Thousands	9 Months Ended
	Sep. 28, 2024 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested at beginning of year, Shares | shares	947
Granted, Shares | shares	749
Vested, Shares | shares	(632)
Canceled, Shares | shares	(19)
Unvested at September 28, 2024, Shares | shares	1,045
Unvested at beginning of year, Grant Date Fair Value Per Share | $ / shares	$ 124.89
Granted, Grant Date Fair Value Per Share | $ / shares	168.85
Vested, Grant Date Fair Value Per Share | $ / shares	143.23
Canceled, Grant Date Fair Value Per Share | $ / shares	149.35
Unvested at September 28, 2024, Grant Date Fair Value Per Share | $ / shares	$ 144.87