Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 106,588	$ 25,308
Accounts receivable, less allowances of $5,530 in 2021 and $5,666 in 2020	276,755	216,899
Prepaid expenses	20,329	19,505
Income tax receivable		96
Other current assets	12,583	9,888
Total current assets	416,255	271,696
Property and Equipment, at cost	2,144,528	1,901,244
Less-accumulated depreciation and amortization	864,074	765,217
Net property and equipment	1,280,454	1,136,027
Operating Lease Right-of-Use Assets	107,781	113,715
Goodwill	12,105	12,105
Identifiable Intangibles, net	7,052	8,216
Other Noncurrent Assets	21,603	7,015
Total assets	1,845,250	1,548,774
Current Liabilities:
Accounts payable	114,010	89,381
Wages, vacation and employees’ benefits	73,109	55,392
Claims and insurance accruals	54,717	49,613
Other current liabilities	38,551	40,571
Current portion of long-term debt	19,396	20,588
Current portion of operating lease liability	21,565	20,209
Total current liabilities	321,348	275,754
Other Liabilities:
Long-term debt, less current portion	31,008	50,388
Operating lease liability, less current portion	88,409	95,321
Deferred income taxes	124,137	119,818
Claims, insurance and other	60,015	46,205
Total other liabilities	303,569	311,732
Stockholders’ Equity:
Preferred stock, $0.001 par value, 50,000 shares authorized, none issued and outstanding
Common stock, $0.001 par value, 50,000,000 shares authorized, 26,336,589 and 26,236,570 shares issued and outstanding at December 31, 2021 and 2020, respectively	26	26
Additional paid-in-capital	274,633	267,666
Deferred compensation trust, 94,627 and 91,888 shares of common stock at cost at December 31, 2021 and 2020, respectively	(4,101)	(2,944)
Retained earnings	949,775	696,540
Total stockholders’ equity	1,220,333	961,288
Total liabilities and stockholders’ equity	$ 1,845,250	$ 1,548,774