Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 529	$ 4,720
Accounts receivable, net	197,973	170,278
Prepaid expenses and other	26,155	28,251
Total current assets	224,657	203,249
Property and Equipment, at cost	1,445,049	1,289,994
Less-accumulated depreciation	609,324	554,214
Net property and equipment	835,725	735,780
Goodwill and Identifiable Intangibles, net	23,005	24,027
Other Noncurrent Assets	4,705	4,259
Total assets	1,088,092	967,315
Current Liabilities:
Accounts payable	62,025	57,438
Wages, vacation and employees’ benefits	53,175	39,748
Claims and insurance accruals	39,846	35,850
Other current liabilities	37,083	19,807
Current portion of long-term debt	17,622	14,083
Total current liabilities	209,751	166,926
Other Liabilities:
Long-term debt, less current portion	103,715	118,833
Deferred income taxes	65,895	59,423
Claims, insurance and other	39,440	39,639
Total other liabilities	209,050	217,895
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, 25,693,651 and 25,551,617 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively	26	26
Additional paid-in-capital	253,366	246,454
Deferred compensation trust, 140,882 and 170,310 shares of common stock at cost at September 30, 2018 and December 31, 2017, respectively	(3,202)	(3,486)
Retained earnings	419,101	339,500
Total stockholders’ equity	669,291	582,494
Total liabilities and stockholders’ equity	$ 1,088,092	$ 967,315