REPORTABLE SEGMENTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	$ 1,569.4	$ 1,773.3	$ 1,556.8
Income from operations	36.2	98.4	112.8
Depreciation	100.1	85.9	81.2
Amortization of intangible assets	6.4	6.9	6.9
Impairment	17.9	9.4	0.0
Restructuring	0.5	2.4	0.3
Non-cash operating lease expense	(0.1)	0.0	0.8
Interest expense	52.2	35.4	33.5
Total property and equipment additions	187.7	187.4	118.4
Company freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	654.9	650.3	629.7
Owner operator freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	422.3	509.9	486.5
Brokerage
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	242.1	321.2	269.0
Logistics
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	59.9	53.8	39.2
Fuel surcharge
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	190.2	238.1	132.4
Flatbed Solution segment
Segment Reporting Information, Profit (Loss) [Abstract]
Intersegment revenues and expenses	5.5	2.7	4.8
Restructuring	0.0
Flatbed Solution segment | Consolidated
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	644.9	769.0	690.0
Income from operations	7.9	39.1	53.3
Depreciation	47.8	37.4	32.7
Amortization of intangible assets	2.4	3.0	3.0
Impairment		0.0
Restructuring	0.0	1.0	0.0
Non-cash operating lease expense	(0.1)	0.0	0.9
Interest expense	21.7	15.1	14.7
Total property and equipment additions	69.3	76.6	37.9
Flatbed Solution segment | Consolidated | Company freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	177.9	167.2	176.6
Flatbed Solution segment | Consolidated | Owner operator freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	282.3	329.2	328.0
Flatbed Solution segment | Consolidated | Brokerage
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	87.7	152.5	112.2
Flatbed Solution segment | Consolidated | Logistics
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	4.8	4.1	4.9
Flatbed Solution segment | Consolidated | Fuel surcharge
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	92.2	116.0	68.3
Specialized
Segment Reporting Information, Profit (Loss) [Abstract]
Intersegment revenues and expenses	5.9	7.9	7.4
Restructuring	0.5
Specialized | Consolidated
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	924.5	1,004.3	866.8
Income from operations	28.3	59.3	59.5
Depreciation	52.3	48.5	48.5
Amortization of intangible assets	4.0	3.9	3.9
Impairment		9.4
Restructuring	0.5	1.4	0.3
Non-cash operating lease expense	0.0	0.0	(0.1)
Interest expense	30.5	20.3	18.8
Total property and equipment additions	118.4	110.8	80.5
Specialized | Consolidated | Company freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	477.0	483.1	453.1
Specialized | Consolidated | Owner operator freight
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	140.0	180.7	158.5
Specialized | Consolidated | Brokerage
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	154.4	168.7	156.8
Specialized | Consolidated | Logistics
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	55.1	49.7	34.3
Specialized | Consolidated | Fuel surcharge
Segment Reporting Information, Profit (Loss) [Abstract]
Total revenue	$ 98.0	$ 122.1	$ 64.1