Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 13,932	$ 8,763
Marketable securities	8,031	6,534
Accounts receivable – net of allowance for doubtful accounts of $7,841 and $5,140, respectively	341,398	259,154
Other receivables	26,318	22,422
Prepaid expenses and other	30,209	23,427
Due from affiliates	807	1,224
Total current assets	420,695	321,524
Property and equipment, net	345,583	364,795
Operating lease right-of-use asset	105,859	97,820
Goodwill	170,730	170,730
Intangible assets – net of accumulated amortization of $107,461 and $93,574, respectively	88,349	102,236
Deferred income taxes	2,060	2,159
Other assets	4,215	3,785
Total assets	1,137,491	1,063,049
Current liabilities:
Accounts payable	117,837	97,916
Current portion of long-term debt	61,160	59,713
Current portion of operating lease liabilities	24,566	21,920
Accrued expenses and other current liabilities	43,627	39,588
Insurance and claims	43,357	25,022
Due to affiliates	17,839	17,093
Income taxes payable	4,323	11,555
Total current liabilities	312,709	272,807
Long-term liabilities:
Long-term debt, net of current portion	366,188	400,407
Operating lease liability, net of current portion	85,984	78,093
Deferred income taxes	61,250	64,426
Other long-term liabilities	9,150	7,743
Total long-term liabilities	522,572	550,669
Shareholders' equity:
Common stock, no par value. Authorized 100,000,000 shares; 30,986,702 and 30,979,827 shares issued; 26,919,455 and 26,912,580 shares outstanding, respectively	30,988	30,981
Paid-in capital	4,639	4,484
Treasury stock, at cost; 4,067,247 shares	(82,385)	(82,385)
Retained earnings	356,071	293,643
Accumulated other comprehensive income (loss):
Interest rate swaps, net of income taxes of $(60) and $(142), respectively	(178)	(476)
Foreign currency translation adjustments	(6,925)	(6,674)
Total shareholders’ equity	302,210	239,573
Total liabilities and shareholders’ equity	$ 1,137,491	$ 1,063,049