Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net income (loss)	$ 11,141	$ 17,632	$ (3,043)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Impairments of assets held for sale and equity method investments and note receivable			6,793
Equity in loss of affiliated companies			270
Deferred income tax provision (benefit)	(861)	4,470	714
Depreciation and amortization	82,975	90,116	90,484
(Gains) Losses on sale of equipment	(999)	12,711	3,853
Share based compensation	6,244	4,395	3,846
Other	684	3,367	660
Unrealized gain on equity investment	(7,677)
Gain on sale of subsidiary			(831)
Changes in operating assets and liabilities, net of acquisitions:
Receivables	(38,556)	(10,048)	7,149
Prepaid insurance and licenses	398	(2,939)	(3,294)
Operating supplies	(465)	(900)	70
Other assets	(20,578)	(3,718)	(7,790)
Accounts payable and other accrued liabilities	41,345	19,940	5,572
Accrued wages and benefits	4,916	15,863	(704)
Net cash provided by operating activities	78,567	150,889	103,749
Investing activities
Payments for purchases of property and equipment	(192,366)	(186,122)	(151,751)
Proceeds from sales of property and equipment	95,369	81,399	77,966
Other		(6,880)	(2,000)
Sale of subsidiary, net of cash			(5,845)
Net cash used in investing activities	(96,997)	(111,603)	(81,630)
Financing activities
Borrowings under lines of credit	334,512	278,654	107,300
Payments under lines of credit	(310,612)	(278,654)	(107,300)
Borrowings under long-term debt	124,721	263,992	106,341
Payments of long-term debt and finance leases	(137,661)	(301,059)	(136,228)
Payments of financing costs	(100)	(1,391)	(190)
Payments of long-term consideration for business acquisition		(1,000)	(990)
Tax withholding related to net share settlement of restricted stock awards	(1,237)	(135)	(44)
Proceeds from issuance of common stock under ESPP	1,284	851	349
Purchase of noncontrolling interest			(8,659)
Proceeds from long-term consideration for sale of subsidiary	617	587
Book overdraft	7,096	(1,313)	1,313
Net cash provided by (used in) financing activities	18,620	(39,468)	(38,108)
Cash included in assets held for sale			11,784
Net change in cash and cash equivalents	190	(182)	(4,205)
Cash and cash equivalents.
Beginning of year	5,505	5,687	9,892
End of period	5,695	5,505	5,687
Supplemental disclosure of cash flow information
Cash paid during the year for interest	13,916	17,620	21,136
Cash paid during the year for income taxes	995	705	58
Supplemental disclosure of significant noncash investing and financing activities
Subsidiary stock issued in business combination		7,278
Finance lease additions	5,572		40
Debt obligations relieved in conjunction with the divesture of Xpress Internacional			7,109
Uncollected proceeds from asset sales	2,581	406	62
Property and equipment amounts accrued in accounts payable	$ 1,656	$ 867	$ 3,552