CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Net sales
Total net sales	$ 4,587,057	$ 5,651,707	$ 14,561,893	$ 17,434,487
Costs of goods sold	3,635,038	4,187,278	11,246,894	12,304,203
Gross profit	952,019	1,464,429	3,314,999	5,130,284
Selling, general and administrative expenses	145,896	132,627	431,414	403,019
Profit sharing	64,413	105,122	224,978	373,333
Amortization of intangible assets	8,160	6,836	25,962	21,158
Operating income	733,550	1,219,844	2,632,645	4,332,774
Interest expense, net of capitalized interest	18,415	25,347	61,689	67,683
Other (income) expense, net	(39,464)	(13,975)	(105,748)	2,472
Income before income taxes	754,599	1,208,472	2,676,704	4,262,619
Income tax expense	174,817	289,997	636,412	1,022,138
Net income	579,782	918,475	2,040,292	3,240,481
Net income attributable to noncontrolling interests	(2,587)	(4,150)	(13,680)	(12,671)
Net income attributable to Steel Dynamics, Inc.	$ 577,195	$ 914,325	$ 2,026,612	$ 3,227,810
Basic earnings per share attributable to Steel Dynamics, Inc. stockholders (in dollars per share)	$ 3.49	$ 5.07	$ 12.04	$ 17.33
Weighted average common shares outstanding (in shares)	165,170	180,264	168,259	186,288
Diluted earnings per share attributable to Steel Dynamics, Inc. stockholders, including the effect of assumed conversions when dilutive (in dollars per share)	$ 3.47	$ 5.03	$ 11.98	$ 17.21
Weighted average common shares and share equivalents outstanding (in shares)	166,105	181,613	169,150	187,531
Dividends declared per share (in dollars per share)	$ 0.425	$ 0.34	$ 1.275	$ 1.02
Unrelated parties
Net sales
Net Sales	$ 4,408,861	$ 5,438,747	$ 14,061,569	$ 16,814,051
Related Parties
Net sales
Net Sales	$ 178,196	$ 212,960	$ 500,324	$ 620,436