Consolidated Condensed Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 187	$ 13,650
Receivables:
Trade, net	73,202	70,869
Other	4,905	4,142
Prepaid expenses and other	13,481	15,274
Deferred income taxes	3,588	3,415
Total current assets	95,363	107,350
Property and equipment:
Accumulated depreciation	(174,951)	(164,916)
Net property and equipment	467,320	415,009
Other assets	3,923	3,443
TOTAL ASSETS	566,606	525,802
Current liabilities:
Checks issued in excess of cash balances	28
Accounts payable and accrued liabilities	38,709	38,624
Insurance and claims accruals	13,759	14,404
Total current liabilities	52,496	53,028
Long-term debt	24,681
Deferred income taxes	110,015	113,637
Total liabilities	187,192	166,665
Stockholders’ equity:
Preferred stock, $.01 par value per share; 2,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $.01 par value per share; 48,000,000 shares authorized; 33,405,829 shares at September 30, 2014, and 33,301,048 shares at December 31, 2013, issued and outstanding	334	333
Additional paid-in capital	86,992	85,077
Retained earnings	292,088	273,727
Total stockholders’ equity	379,414	359,137
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	566,606	525,802
Office Equipment And Other [Member]
Property and equipment:
Revenue equipment, buildings and land, office equipment and other	$ 642,271	$ 579,925