Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current Assets:
Cash and cash equivalents	$ 31	$ 2,194
Accounts receivable, net	202,133	181,612
Prepaid expenses and other	38,923	29,567
Total current assets	241,087	213,373
Property and Equipment, at cost	1,553,938	1,521,341
Less-accumulated depreciation	648,408	628,283
Net property and equipment	905,530	893,058
Operating Lease Right-of-Use Assets	72,460
Goodwill and Identifiable Intangibles, net	22,356	22,664
Other Noncurrent Assets	5,424	4,648
Total assets	1,246,857	1,133,743
Current Liabilities:
Accounts payable	71,983	78,994
Wages, vacation and employees’ benefits	38,834	48,116
Claims and insurance accruals	40,138	40,980
Other current liabilities	25,207	23,138
Current portion of long-term debt	17,914	18,082
Current portion of operating lease liability	17,390
Total current liabilities	211,466	209,310
Other Liabilities:
Long-term debt, less current portion	130,964	104,777
Operating lease liability, less current portion	58,035
Deferred income taxes	92,208	86,893
Claims, insurance and other	36,534	36,899
Total other liabilities	317,741	228,569
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, 25,890,176 and 25,693,651 shares issued and outstanding at March 31, 2019 and December 31, 2018, respectively	26	26
Additional paid-in-capital	254,575	254,738
Deferred compensation trust, 144,536 and 143,614 shares of common stock at cost at March 31, 2019 and December 31, 2018, respectively	(3,691)	(3,381)
Retained earnings	466,740	444,481
Total stockholders’ equity	717,650	695,864
Total liabilities and stockholders’ equity	$ 1,246,857	$ 1,133,743