Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 4,720	$ 1,539
Accounts receivable, less allowances of $3,991 in 2017 and $3,222 in 2016	170,610	135,083
Prepaid expenses and other	17,540	17,369
Income tax receivable	3,664	6,989
Other current assets	7,047	5,499
Total current assets	203,581	166,479
Property and Equipment, at cost	1,289,994	1,101,946
Less-accumulated depreciation	554,214	497,827
Net property and equipment	735,780	604,119
Goodwill	12,105	12,105
Identifiable Intangibles, net	11,922	13,293
Other Noncurrent Assets	4,259	4,374
Total assets	967,647	800,370
Current Liabilities:
Accounts payable	57,717	45,149
Wages, vacation and employees’ benefits	39,748	31,700
Claims and insurance accruals	35,850	33,047
Other current liabilities	19,807	18,286
Current portion of long-term debt	14,083	16,762
Total current liabilities	167,205	144,944
Other Liabilities:
Long-term debt, less current portion	118,833	57,042
Deferred income taxes	59,423	80,199
Claims, insurance and other	39,639	35,107
Total other liabilities	217,895	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, 25,551,617 and 25,322,701 shares issued and outstanding at December 31, 2017 and 2016, respectively	26	25
Additional paid-in-capital	246,454	237,846
Deferred compensation trust, 170,310 and 166,807 shares of common stock at cost at December 31, 2017 and 2016, respectively	(3,486)	(3,190)
Retained earnings	339,553	248,397
Total stockholders’ equity	582,547	483,078
Total liabilities and stockholders’ equity	$ 967,647	$ 800,370