Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net income	$ 46,693	$ 26,559
Adjustments to reconcile net income to net cash provided (used) by operating activities:
Provision for losses on accounts receivable	(26)	833
(Reversal) deferral of gain on sales to equity method investee	(30)	53
Depreciation and amortization	27,377	27,951
Deferred income tax expense	620	7,274
Income tax expense arising from restricted share vesting and stock options exercised	(40)	(255)
Stock-based compensation expense	3,748	4,946
Income from equity method investment	(13,861)	(6,342)
Gain on disposition of property and equipment	(566)	(2,812)
Gain on reversal of contingent loss of discontinued operations	0	(3,412)
Gain on investment in available-for-sale securities	0	(63)
Changes in operating assets and liabilities:
Receivables and advances	21,450	(44,671)
Prepaid expenses and other assets	2,074	547
Inventory and supplies	(638)	(436)
Insurance and claims accrual	(6,332)	7,854
Accounts payable and accrued expenses	(3,566)	16,097
Net cash flows provided by operating activities	76,903	34,123
Cash flows from investing activities:
Acquisition of AAT Carriers, Inc., net of cash acquired	(37,324)	0
Other investment	(12)	(13)
Purchase of available-for-sale securities	0	(33)
Purchase of property and equipment	(27,560)	(13,971)
Proceeds from disposition of property and equipment	1,931	33,797
Net cash flows (used) provided by investing activities	(62,965)	19,780
Cash flows from financing activities:
Change in checks outstanding in excess of bank balances	(216)	(1,215)
Cash dividend	(2,022)	0
Proceeds from issuance of notes payable	35,917	0
Repayments of notes payable	(3,526)	(9,383)
Repayments of finance lease obligations	(4,295)	(1,481)
Proceeds under revolving credit facility	85,632	446,978
Repayments under revolving credit facility and draw note	(85,632)	(482,996)
Payment of minimum tax withholdings on stock compensation	(380)	(887)
Common stock repurchased	(43,365)	(8,360)
Net cash flows provided (used) by financing activities	(17,887)	(57,344)
Net change in cash and cash equivalents	(3,949)	(3,441)
Cash and cash equivalents at beginning of period	8,412	8,407
Cash and cash equivalents at end of period	$ 4,463	$ 4,966