CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 196,746	$ 362,572	$ 401,573	$ 588,047
Other comprehensive loss - net unrealized loss on cash flow hedging derivatives, net of income tax benefit	(52)	(105)	(223)	(105)
Comprehensive income	196,694	362,467	401,350	587,942
Comprehensive (income) loss attributable to noncontrolling interests	(2,444)	(123)	(2,943)	1,953
Comprehensive income attributable to Steel Dynamics, Inc.	$ 194,250	$ 362,344	$ 398,407	$ 589,895