Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net income (loss)	$ 42,999	$ (17,055)
Adjustments to reconcile net income to net cash provided (used) by operating activities:
Provision for losses on accounts receivable	1,045	3,211
Reversal (deferral) of gain on sales to equity method investee	53	(77)
Depreciation and amortization	41,316	51,281
Impairment of property and equipment	0	26,569
Amortization of deferred financing fees	0	154
Deferred income tax expense (benefit)	12,911	(7,138)
Income tax (expense) benefit arising from restricted share vesting and stock options exercised	(216)	81
Stock-based compensation expense	6,803	1,120
Income from equity method investment	(9,572)	(971)
Return on investment in equity method investee	1,960	0
Gain on disposition of property and equipment	(3,683)	(7,019)
Gain on disposition of reportable segment	0	(3,720)
Gain on reversal of contingent loss of discontinued operations	(3,412)	0
Gain on investment in available-for-sale securities	(63)	0
Changes in operating assets and liabilities:
Receivables and advances	(72,848)	(72,413)
Prepaid expenses and other assets	1,501	5,756
Inventory and supplies	(540)	914
Insurance and claims accrual	25,153	30,428
Accounts payable and accrued expenses	24,831	13,836
Net cash flows provided by operating activities	68,238	24,957
Cash flows from investing activities:
Other investment	(13)	0
Purchase of available-for-sale securities	(33)	(319)
Acquisition of property and equipment	(21,801)	(63,614)
Proceeds from disposition of reportable segment	0	108,375
Proceeds from dispositions of property and equipment	43,812	86,555
Net cash flows provided by investing activities	21,965	130,997
Cash flows from financing activities:
Change in checks outstanding in excess of bank balances	(1,215)	(592)
Proceeds from issuance of notes payable	0	65,457
Repayments of notes payable	(10,058)	(215,750)
Repayments of finance lease obligations	(3,193)	(17,372)
Proceeds under revolving credit facility	535,199	1,091,966
Repayments under revolving credit facility and draw note	(585,838)	(1,091,966)
Payment of minimum tax withholdings on stock compensation	(969)	(68)
Common stock repurchased	(10,348)	(17,486)
Net cash flows used by financing activities	(76,422)	(185,811)
Net change in cash and cash equivalents	13,781	(29,857)
Cash and cash equivalents at beginning of period	8,407	43,591
Cash and cash equivalents at end of period	$ 22,188	$ 13,734