SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Condensed Consolidating Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Income Statements, Captions [Line Items]
Revenue									$ 1,478.7	$ 1,506.4	$ 1,336.0
Cost of goods sold before depreciation, depletion and amortization									1,187.6	1,212.2	1,056.6
Selling, general and administrative expenses									130.0	126.5	119.2
Depreciation, depletion and amortization									93.2	91.8	67.8
Change in value of contingent consideration									2.8	0.0	7.9
Impairment of goodwill and other assets									0.0	1.3	6.2
Gain on sale/disposal of assets and business, net									(0.1)	(15.3)	(0.7)
Operating income	$ 18.0	$ 33.3	$ 6.0	$ 7.9	$ 16.7	$ 35.0	$ 30.6	$ 7.6	65.2	89.9	79.0
Interest expense, net									46.1	46.4	42.1
Derivative loss									0.0	0.0	0.8
Other income, net									(9.5)	(4.6)	(2.5)
Income from continuing operations before income taxes									28.6	48.1	38.6
Income tax expense									12.3	16.8	12.4
Income from continuing operations									16.3	31.3	26.2
Loss from discontinued operations, net of taxes									0.0	0.0	(0.6)
Net income (loss) before equity in earnings of subsidiaries and non-controlling interest									16.3	31.3	25.6
Net income (loss) before equity in earnings of subsidiaries and non-controlling interest									0.0	0.0	0.0
Net income	4.4	13.6	0.9	(2.6)	3.1	15.8	16.3	(3.9)	16.3	31.3	25.6
Less: Net income attributable to non-controlling interest									(1.4)	(1.3)	(0.1)
Net income attributable to U.S. Concrete	$ 3.9	$ 13.0	$ 0.7	$ (2.7)	$ 2.0	$ 15.6	$ 16.3	$ (3.9)	14.9	30.0	25.5
Eliminations and Reclassifications
Condensed Income Statements, Captions [Line Items]
Revenue									0.0	0.0	0.0
Cost of goods sold before depreciation, depletion and amortization									0.0	0.0	0.0
Selling, general and administrative expenses									0.0	0.0	0.0
Depreciation, depletion and amortization									0.0	0.0	0.0
Change in value of contingent consideration									0.0	0.0	0.0
Impairment of goodwill and other assets										0.0	0.0
Gain on sale/disposal of assets and business, net									0.0	0.0	0.0
Operating income									0.0	0.0	0.0
Interest expense, net									0.0	0.0	0.0
Derivative loss											0.0
Other income, net									0.0	0.0	0.0
Income from continuing operations before income taxes									0.0	0.0	0.0
Income tax expense									0.0	0.0	0.0
Income from continuing operations											0.0
Loss from discontinued operations, net of taxes											0.0
Net income (loss) before equity in earnings of subsidiaries and non-controlling interest									0.0	0.0	0.0
Net income (loss) before equity in earnings of subsidiaries and non-controlling interest									(39.5)	(66.3)	(50.8)
Net income									(39.5)	(66.3)	(50.8)
Less: Net income attributable to non-controlling interest									0.0	0.0	0.0
Net income attributable to U.S. Concrete									(39.5)	(66.3)	(50.8)
Parent | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Revenue									0.0	0.0	0.0
Cost of goods sold before depreciation, depletion and amortization									0.0	0.0	0.0
Selling, general and administrative expenses									0.0	0.0	0.0
Depreciation, depletion and amortization									0.0	0.0	0.0
Change in value of contingent consideration									0.0	0.1	0.9
Impairment of goodwill and other assets										0.0	0.0
Gain on sale/disposal of assets and business, net									0.0	0.0	0.0
Operating income									0.0	(0.1)	(0.9)
Interest expense, net									39.7	39.5	39.9
Derivative loss											0.8
Other income, net									0.0	1.2	0.0
Income from continuing operations before income taxes									(39.7)	(40.8)	(41.6)
Income tax expense									(15.1)	(4.5)	(16.3)
Income from continuing operations											(25.3)
Loss from discontinued operations, net of taxes											0.0
Net income (loss) before equity in earnings of subsidiaries and non-controlling interest									(24.6)	(36.3)	(25.3)
Net income (loss) before equity in earnings of subsidiaries and non-controlling interest									39.5	66.3	50.8
Net income									14.9	30.0	25.5
Less: Net income attributable to non-controlling interest									0.0	0.0	0.0
Net income attributable to U.S. Concrete									14.9	30.0	25.5
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Revenue									1,361.2	1,394.4	1,311.6
Cost of goods sold before depreciation, depletion and amortization									1,107.6	1,130.8	1,034.3
Selling, general and administrative expenses									122.6	118.5	115.4
Depreciation, depletion and amortization									78.2	76.2	64.1
Change in value of contingent consideration									2.8	(0.1)	7.0
Impairment of goodwill and other assets										1.3	0.0
Gain on sale/disposal of assets and business, net									(0.1)	(15.5)	(0.7)
Operating income									50.1	83.2	91.5
Interest expense, net									3.6	3.7	1.6
Derivative loss											0.0
Other income, net									(7.9)	(3.7)	(2.5)
Income from continuing operations before income taxes									54.4	83.2	92.4
Income tax expense									24.3	18.4	29.0
Income from continuing operations											63.4
Loss from discontinued operations, net of taxes											(0.6)
Net income (loss) before equity in earnings of subsidiaries and non-controlling interest									30.1	64.8	62.8
Net income (loss) before equity in earnings of subsidiaries and non-controlling interest									0.0	0.0	0.0
Net income									30.1	64.8	62.8
Less: Net income attributable to non-controlling interest									0.0	0.0	0.0
Net income attributable to U.S. Concrete									30.1	64.8	62.8
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Income Statements, Captions [Line Items]
Revenue									117.5	112.0	24.4
Cost of goods sold before depreciation, depletion and amortization									80.0	81.4	22.3
Selling, general and administrative expenses									7.4	8.0	3.8
Depreciation, depletion and amortization									15.0	15.6	3.7
Change in value of contingent consideration									0.0	0.0	0.0
Impairment of goodwill and other assets										0.0	6.2
Gain on sale/disposal of assets and business, net									0.0	0.2	0.0
Operating income									15.1	6.8	(11.6)
Interest expense, net									2.8	3.2	0.6
Derivative loss											0.0
Other income, net									(1.6)	(2.1)	0.0
Income from continuing operations before income taxes									13.9	5.7	(12.2)
Income tax expense									3.1	2.9	(0.3)
Income from continuing operations											(11.9)
Loss from discontinued operations, net of taxes											0.0
Net income (loss) before equity in earnings of subsidiaries and non-controlling interest									10.8	2.8	(11.9)
Net income (loss) before equity in earnings of subsidiaries and non-controlling interest									0.0	0.0	0.0
Net income									10.8	2.8	(11.9)
Less: Net income attributable to non-controlling interest									(1.4)	(1.3)	(0.1)
Net income attributable to U.S. Concrete									$ 9.4	$ 1.5	$ (12.0)