Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
CURRENT ASSETS
Cash and cash equivalents	$ 119,838	$ 139,770
Trade receivables, net	46,555	44,198
Prepaid tires	6,603	12,820
Other current assets	2,281	1,932
Income tax receivable	2,351	314
Deferred income taxes, net	13,797	14,401
Total current assets	191,425	213,435
PROPERTY AND EQUIPMENT
Land and land improvements	17,451	17,451
Buildings	26,761	26,761
Furniture and fixtures	2,269	2,269
Shop and service equipment	7,266	7,324
Revenue equipment	378,583	355,905
Property, Plant and Equipment, Gross	432,330	409,710
Less accumulated depreciation	189,959	161,269
Property and equipment, net	242,371	248,441
LONG-TERM INVESTMENTS	20,016	50,569
GOODWILL	4,815	4,815
OTHER ASSETS	9,110	8,406
Assets	467,737	525,666
CURRENT LIABILITIES
Accounts payable and accrued liabilities	7,583	9,088
Compensation and benefits	16,409	15,493
Insurance accruals	13,924	13,997
Other accruals	7,439	7,085
Total current liabilities	45,355	45,663
LONG-TERM LIABILITIES
Income taxes payable	23,122	24,077
Deferred income taxes, net	51,306	57,661
Insurance accruals less current portion	57,590	57,494
Total long-term liabilities	132,018	139,232
COMMITMENTS AND CONTINGENCIES (Note 9)
STOCKHOLDERS' EQUITY
Preferred stock, par value $.01; authorized 5,000 shares; none issued	0	0
Capital stock, common, $.01 par value; authorized 395,000 shares; issued 90,689 in 2012 and 2011; outstanding, 84,770 and 86,475 in 2012 and 2011, respectively	907	907
Additional paid-in capital	2,968	589
Retained earnings	368,313	398,706
Treasury stock, at cost; 5,919 and 4,214 shares in 2012 and 2011, respectively	(80,540)	(56,350)
Accumulated other comprehensive loss	(1,284)	(3,081)
Stockholders' Equity Attributable to Parent	290,364	340,771
Liabilities and Stockholders' Equity	$ 467,737	$ 525,666