Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Agreed-upon price for the exchange of the underlying asset relating to the share-based payment award.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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Rate of weighted-average expected volatility for award under share-based payment arrangement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Share-based Compensation Arrangement By Share-based Payment Award, Award Vesting Rights, Percentage Of Performance Stock Units Granted

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Share-based Compensation Arrangement By Share-based Payment Award, Common Stock, Additional Capital Shares Reserved For Future Issuance

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STOCK-BASED COMPENSATION - Narrative (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions		3 Months Ended
	Mar. 01, 2020	Mar. 31, 2020	Mar. 31, 2019
U.S. Concrete, Inc. Long Term Incentive Plan \| Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares authorized (shares)		23
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense		$ 3.7	$ 1.7
Grants in period (shares)	400
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%
Expected volatility (percentage)		43.80%
Risk-free interest rate (percentage)		0.90%
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)		1 year 1 month
Vesting price (USD per share)		$ 43.23
Grant date fair value per share (USD per share)		$ 11.49
Restricted Stock Units (RSUs) \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (years)		1 year 7 months
Vesting price (USD per share)		$ 55.21
Grant date fair value per share (USD per share)		$ 16.24