Condensed Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2016	Oct. 03, 2015	Oct. 01, 2016	Oct. 03, 2015
Income Statement [Abstract]
Net sales	$ 4,290,236	$ 4,225,514	$ 12,251,584	$ 12,982,563
Costs, expenses and other:
Cost of products sold	3,665,900	3,701,678	10,774,040	11,784,139
Marketing, administrative and other expenses	169,223	124,339	440,679	377,492
Equity in earnings of unconsolidated affiliates	(14,168)	(115)	(30,232)	(550)
Interest expense, net	43,009	45,341	128,415	131,944
Costs, expenses and other, total	3,863,964	3,871,243	11,312,902	12,293,025
Earnings before income taxes and noncontrolling interests	426,272	354,271	938,682	689,538
Provision for income taxes	131,788	86,535	281,401	178,166
Net earnings	294,484	267,736	657,281	511,372
Earnings attributable to noncontrolling interests	24,448	40,610	82,719	91,691
Net earnings attributable to Nucor stockholders	$ 270,036	$ 227,126	$ 574,562	$ 419,681
Net earnings per share:
Basic	$ 0.84	$ 0.71	$ 1.79	$ 1.30
Diluted	$ 0.84	$ 0.71	$ 1.79	$ 1.30
Average shares outstanding:
Basic	319,737	320,819	319,444	320,544
Diluted	320,028	320,900	319,632	320,695
Dividends declared per share	$ 0.3750	$ 0.3725	$ 1.1250	$ 1.1175