Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 166,425	$ 187,390
Accounts receivable, net	294,917	290,306
Prepaid expenses	38,635	22,525
Income tax receivable	6,391	23,438
Other current assets	7,146	7,227
Total current assets	513,514	530,886
Property and Equipment, at cost	2,602,963	2,478,824
Less: accumulated depreciation	1,034,649	996,204
Net property and equipment	1,568,314	1,482,620
Operating Lease Right-of-Use Assets	115,484	120,455
Goodwill and Identifiable Intangibles, net	17,936	18,149
Other Noncurrent Assets	27,551	22,600
Total assets	2,242,799	2,174,710
Current Liabilities:
Accounts payable	108,362	99,792
Wages, vacation and employees’ benefits	54,706	66,684
Claims and insurance accruals	43,276	45,481
Other current liabilities	24,479	22,684
Current portion of long-term debt	14,452	14,519
Current portion of operating lease liability	25,256	24,925
Total current liabilities	270,531	274,085
Other Liabilities:
Long-term debt, less current portion	12,052	16,489
Operating lease liability, less current portion	93,649	98,581
Deferred income taxes	151,509	145,771
Claims, insurance and other	64,118	60,443
Total other liabilities	321,328	321,284
Stockholders’ Equity:
Preferred stock, $0.001 par value, 50,000 shares authorized, none issued and outstanding	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized, 26,532,778 and 26,464,197 shares issued and outstanding at March 31, 2023 and December 31, 2022, respectively	27	26
Additional paid-in-capital	273,274	277,366
Deferred compensation trust, 70,812 and 69,982 shares of common stock at cost at March 31, 2023 and December 31, 2022, respectively	(5,655)	(5,248)
Retained earnings	1,383,294	1,307,197
Total stockholders’ equity	1,650,940	1,579,341
Total liabilities and stockholders’ equity	$ 2,242,799	$ 2,174,710