Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 399	$ 1,539
Accounts receivable, net	167,012	135,083
Prepaid expenses and other	30,219	29,857
Total current assets	197,630	166,479
Property and Equipment, at cost	1,233,906	1,101,946
Less-accumulated depreciation	520,682	497,827
Net property and equipment	713,224	604,119
Goodwill and Identifiable Intangibles, net	24,709	25,398
Other Noncurrent Assets	4,767	4,374
Total assets	940,330	800,370
Current Liabilities:
Accounts payable	55,746	45,149
Wages, vacation and employees’ benefits	40,872	31,700
Claims and insurance accruals	36,131	33,047
Other current liabilities	18,283	18,286
Current portion of long-term debt	16,669	16,762
Total current liabilities	167,701	144,944
Other Liabilities:
Long-term debt, less current portion	131,699	57,042
Deferred income taxes	87,075	80,199
Claims, insurance and other	38,855	35,107
Total other liabilities	257,629	172,348
Commitments and Contingencies
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, 25,450,399 and 25,141,799 shares issued and outstanding at June 30, 2017 and December 31, 2016, respectively	25	25
Additional paid-in-capital	241,057	237,846
Deferred compensation trust, 171,927 and 165,971 shares of common stock at cost at June 30, 2017 and December 31, 2016, respectively	(3,469)	(3,190)
Retained earnings	277,387	248,397
Total stockholders’ equity	515,000	483,078
Total liabilities and stockholders’ equity	$ 940,330	$ 800,370