CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Total net sales	$ 4,632,634	$ 5,081,630	$ 9,326,637	$ 9,974,836
Costs of goods sold	3,857,797	3,774,772	7,571,002	7,611,856
Gross profit	774,837	1,306,858	1,755,635	2,362,980
Selling, general and administrative expenses	160,016	141,209	319,523	285,518
Profit sharing	48,053	90,990	110,705	160,565
Amortization of intangible assets	7,645	10,924	15,309	17,802
Operating income	559,123	1,063,735	1,310,098	1,899,095
Interest expense, net of capitalized interest	12,719	20,767	24,697	43,274
Other (income) expense, net	(18,708)	(31,348)	(45,492)	(66,284)
Income before income taxes	565,112	1,074,316	1,330,893	1,922,105
Income tax expense	133,422	258,139	311,703	461,595
Net income	431,690	816,177	1,019,190	1,460,510
Net income attributable to noncontrolling interests	(3,692)	(4,070)	(7,151)	(11,093)
Net income attributable to Steel Dynamics, Inc.	$ 427,998	$ 812,107	$ 1,012,039	$ 1,449,417
Basic earnings per share attributable to Steel Dynamics, Inc. stockholders (in dollars per share)	$ 2.73	$ 4.83	$ 6.42	$ 8.54
Weighted average common shares outstanding (in shares)	156,856	168,009	157,761	169,803
Diluted earnings per share attributable to Steel Dynamics, Inc. stockholders, including the effect of assumed conversions when dilutive (in dollars per share)	$ 2.72	$ 4.81	$ 6.39	$ 8.49
Weighted average common shares and share equivalents outstanding (in shares)	157,579	168,865	158,467	170,672
Dividends declared per share (in dollars per share)	$ 0.46	$ 0.425	$ 0.92	$ 0.85
Unrelated parties
Total net sales	$ 4,443,994	$ 4,930,422	$ 8,940,813	$ 9,675,775
Related parties
Total net sales	$ 188,640	$ 151,208	$ 385,824	$ 299,061