Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 11,140	$ (2,213)
Adjustments to reconcile net income to net cash provided (used) by operating activities:
Provision for losses on accounts receivable	402	320
Reversal (deferral) of gain on sales to equity method investee	45	(2)
Depreciation and amortization	14,087	18,187
Amortization of deferred financing fees	0	37
Deferred income tax expense (benefit)	4,735	(904)
Income tax (expense) benefit arising from restricted share vesting and stock options exercised	(120)	9
Stock-based compensation expense	2,594	466
(Income) Loss from equity method investment	(2,960)	735
Gain on disposition of property and equipment	(923)	(1,524)
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	(6,917)	(48,218)
Prepaid expenses and other assets	(1,064)	3,802
Inventory and supplies	(352)	398
Insurance and claims accrual	(8,739)	22,805
Accounts payable and accrued expenses	1,163	2,586
Net cash flows provided (used) by operating activities	9,616	(3,516)
Cash flows from investing activities:
Purchase of available-for-sale securities	(33)	245
Acquisition of property and equipment	(3,907)	(35,240)
Proceeds from disposition of property and equipment	13,871	18,497
Net cash flows provided (used) by investing activities	9,931	(16,498)
Cash flows from financing activities:
Change in checks outstanding in excess of bank balances	(646)	(111)
Proceeds from issuance of notes payable	0	29,746
Repayments of notes payable	(8,713)	(18,993)
Repayments of finance lease obligations	(633)	(1,305)
Proceeds under revolving credit facility	216,128	411,981
Repayments under revolving credit facility	(220,651)	(387,719)
Payment of minimum tax withholdings on stock compensation	(531)	(6)
Common stock repurchased	(8,118)	(17,515)
Net cash flows (used) provided by financing activities	(23,164)	16,078
Net change in cash and cash equivalents	(3,617)	(3,936)
Cash and cash equivalents at beginning of period	8,407	43,591
Cash and cash equivalents at end of period	$ 4,790	$ 39,655