CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities
Net income (loss)	$ (17.7)	$ 50.2	$ 56.0
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	100.1	85.9	81.2
Amortization of intangible assets	6.4	6.9	6.9
Amortization of deferred financing fees	2.1	1.3	2.9
Non-cash operating lease expense	(0.1)	0.0	0.8
Change in fair value of warrant liability	0.0	(4.7)	(1.6)
Stock-based compensation expense	8.5	11.5	8.6
Deferred taxes	(2.0)	10.9	14.7
Bad debt expense (recovery)	0.0	0.7	(0.3)
Gain on disposition of property and equipment	(12.3)	(21.0)	(17.1)
Impairment	17.9	9.4	0.0
Changes in operating assets and liabilities
Accounts receivable	21.5	(4.7)	(17.7)
Drivers' advances and other receivables	(2.7)	(2.6)	0.9
Other current assets	3.1	(13.1)	3.9
Income tax receivable	(2.2)	0.0	0.0
Accounts payable	(0.3)	0.1	(1.8)
Accrued expenses and other liabilities	(3.6)	6.2	7.3
Net cash provided by operating activities	118.7	137.0	144.7
Cash flows from investing activities
Purchase of property and equipment	(30.3)	(42.1)	(53.7)
Proceeds from sale of property and equipment	31.0	40.9	58.6
Cash paid for acquisitions, net of cash received	0.0	(19.1)	0.0
Net cash provided by (used in) investing activities	0.7	(20.3)	4.9
Cash flows from financing activities:
Advances on line of credit	1,644.9	1,831.3	1,656.3
Repayments on line of credit	(1,644.9)	(1,831.3)	(1,656.3)
Principal payments on long-term debt	(166.5)	(71.7)	(247.4)
Proceeds from long-term debt	0.0	0.0	97.5
Payments of deferred financing fees	0.0	0.0	(3.4)
Repurchase of common stock	0.0	(44.9)	(20.4)
Exercise of stock options, net	0.1	0.8	0.5
Exercise of warrants	0.0	9.4	0.0
Net cash used in financing activities	(196.4)	(111.4)	(178.2)
Effect of exchange rates on cash and cash equivalents	0.2	0.6	(0.1)
Net (decrease) increase in cash and cash equivalents	(76.8)	5.9	(28.7)
Cash and cash equivalents - beginning of period	153.4	147.5	176.2
Cash and cash equivalents - end of period	76.6	153.4	147.5
Supplemental disclosure of cash flow information
Cash paid for interest	50.0	34.3	29.6
Cash paid for income taxes	6.2	22.0	10.4
Noncash investing and financing activities
Property and equipment acquired with debt or finance lease obligations	157.4	145.3	64.7
Property and equipment sold for notes receivable	0.0	0.0	0.5
Right-of-use assets acquired	31.5	36.0	23.6
Accrued share repurchase excise taxes	0.1	0.0	0.0
Series B perpetual preferred stock
Noncash investing and financing activities
Accrued Series B perpetual preferred stock dividend	0.0	0.7	0.0
Series A
Cash flows from financing activities:
Convertible preferred stock dividends	(5.0)	(5.0)	(5.0)
Series B
Cash flows from financing activities:
Convertible preferred stock dividends	(5.0)	0.0	$ 0.0
Series B perpetual preferred stock redemption	$ (20.0)	$ 0.0