STOCK-BASED COMPENSATION (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended		6 Months Ended
	Feb. 22, 2021	Mar. 01, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Mar. 01, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			$ 14.7	$ 2.5	$ 17.6	$ 6.2
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period (shares)		367,720
Percentage of plan that is time-vested (percentage)		60.00%
Award vesting period (years)					3 years
Percentage of plan that is performance based (percentage)		40.00%
Percentage of performance stock units granted (percentage)		200.00%
Share price (USD per share)							$ 55.72
Granted in period, fair value			$ 8.1
Expected volatility (percentage)					72.90%
Risk-free interest rate (percentage)					0.30%
Cost not yet recognized, period for recognition			3 months 18 days
Number of consecutive trading days					20 days
Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (years)					3 months 18 days
Vesting price (USD per share)			$ 69.23		$ 69.23
Grant date fair value per share (USD per share)					$ 49.65
Restricted Stock Units (RSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (years)					4 months 24 days
Vesting price (USD per share)			$ 74.95		$ 74.95
Grant date fair value per share (USD per share)					$ 47.97
U.S. Concrete, Inc. Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares authorized (shares)	880,000
Common stock reserved for future issuance (shares)			485,000		485,000