REPORTABLE SEGMENTS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	$ 351.7	$ 450.6	$ 742.7	$ 883.6
Operating income (loss)	12.4	4.7	4.1	5.4
Depreciation	21.0	35.8	45.5	73.0
Amortization of intangible assets	1.8	3.9	3.6	8.2
Impairment			13.4
Restructuring	3.0		3.5
Non-cash operating lease expense	(0.2)	6.7	2.7	13.3
Interest expense	11.0	12.7	23.0	25.4
Income (loss) before income tax	2.6	(7.1)	(18.6)	(18.3)
Total assets	1,134.0	1,503.0	1,134.0	1,503.0	$ 1,140.6
Cash capital expenditures	30.6	31.0	44.9	60.0
Company freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	167.0	206.9	347.9	413.1
Owner operator freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	96.0	121.7	203.8	232.7
Brokerage
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	57.9	72.8	119.6	144.2
Logistics
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	8.8	13.1	18.9	25.5
Fuel surcharge
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	22.0	36.1	52.5	68.1
Corporate/Eliminations
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	(7.0)	(5.0)	(11.6)	(9.6)
Operating income (loss)	(12.8)	(12.5)	(23.2)	(22.8)
Depreciation	0.3	0.1	0.6	0.2
Non-cash operating lease expense		0.1		0.2
Interest expense	5.8	6.7	12.2	13.5
Income (loss) before income tax	(18.4)	(18.7)	(35.0)	(35.8)
Total assets	187.8	69.1	187.8	69.1
Cash capital expenditures		0.4		1.0
Corporate/Eliminations | Company freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	(3.5)	(2.6)	(6.0)	(5.5)
Corporate/Eliminations | Owner operator freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	(2.4)	(1.3)	(3.5)	(2.6)
Corporate/Eliminations | Brokerage
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	(0.7)	(0.6)	(1.4)	(0.6)
Corporate/Eliminations | Logistics
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue			0.1
Corporate/Eliminations | Fuel surcharge
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	(0.4)	(0.5)	(0.8)	(0.9)
Flatbed
Segment Reporting Information, Profit (Loss) [Abstract]
Intersegment revenues and expenses	1.8	2.5	3.5	4.6
Insurance costs included in the corporate segment		1.4		2.2
Flatbed | Consolidated
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	137.2	174.9	292.4	343.0
Operating income (loss)	10.7	6.1	19.3	9.4
Depreciation	8.5	12.3	16.8	25.4
Amortization of intangible assets	0.8	1.3	1.6	3.0
Restructuring	0.2		0.2
Non-cash operating lease expense	1.2	3.1	2.1	5.5
Interest expense	2.4	2.7	4.9	5.3
Income (loss) before income tax	8.5	3.5	14.6	4.4
Total assets	341.2	501.5	341.2	501.5
Cash capital expenditures	9.2	15.8	17.0	30.5
Flatbed | Consolidated | Company freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	48.9	55.0	100.2	110.2
Flatbed | Consolidated | Owner operator freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	60.1	73.4	126.3	142.0
Flatbed | Consolidated | Brokerage
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	15.5	25.7	35.0	51.1
Flatbed | Consolidated | Logistics
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	0.7	0.6	1.5	1.3
Flatbed | Consolidated | Fuel surcharge
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	12.0	20.2	29.4	38.4
Specialized
Segment Reporting Information, Profit (Loss) [Abstract]
Intersegment revenues and expenses	4.8	2.0	7.5	4.1
Insurance costs included in the corporate segment		4.9		5.9
Specialized | Consolidated
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	221.5	280.7	461.9	550.2
Operating income (loss)	14.5	11.1	8.0	18.8
Depreciation	12.2	23.4	28.1	47.4
Amortization of intangible assets	1.0	2.6	2.0	5.2
Impairment			13.4
Restructuring	2.8		3.3
Non-cash operating lease expense	(1.4)	3.5	0.6	7.6
Interest expense	2.8	3.3	5.9	6.6
Income (loss) before income tax	12.5	8.1	1.8	13.1
Total assets	605.0	932.4	605.0	932.4
Cash capital expenditures	21.4	14.8	27.9	28.5
Specialized | Consolidated | Company freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	121.6	154.5	253.7	308.4
Specialized | Consolidated | Owner operator freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	38.3	49.6	81.0	93.3
Specialized | Consolidated | Brokerage
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	43.1	47.7	86.0	93.7
Specialized | Consolidated | Logistics
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	8.1	12.5	17.3	24.2
Specialized | Consolidated | Fuel surcharge
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	$ 10.4	$ 16.4	$ 23.9	$ 30.6