Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
CURRENT ASSETS
Cash and cash equivalents	$ 164,215	$ 119,838
Short-term Investments	6,850
Trade receivables, net	48,112	46,555
Prepaid tires	4,806	6,603
Other current assets	5,689	2,281
Income tax receivable	4,119	2,351
Deferred income taxes, net	12,509	13,797
Total current assets	246,300	191,425
PROPERTY AND EQUIPMENT
Land and land improvements	17,098	17,451
Buildings	27,673	26,761
Furniture and fixtures	2,284	2,269
Shop and service equipment	7,266	7,266
Revenue equipment	395,573	378,583
Property, Plant and Equipment, Gross	449,894	432,330
Less accumulated depreciation	177,206	189,959
Property and equipment, net	272,688	242,371
LONG-TERM INVESTMENTS	4,345	20,016
GOODWILL	4,815	4,815
OTHER ASSETS	9,304	9,110
Assets	537,452	467,737
CURRENT LIABILITIES
Accounts payable and accrued liabilities	28,825	7,583
Compensation and benefits	18,235	16,409
Insurance accruals	11,934	13,924
Other accruals	7,535	7,439
Total current liabilities	66,529	45,355
LONG-TERM LIABILITIES
Income taxes payable	19,708	23,122
Deferred income taxes, net	55,345	51,306
Insurance accruals less current portion	54,008	57,590
Total long-term liabilities	129,061	132,018
COMMITMENTS AND CONTINGENCIES (Note 11)
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 2013 and 2012; outstanding, 84,837 in 2013 and 84,770 in 2012	907	907
Additional paid-in capital	3,774	2,968
Retained earnings	417,951	368,313
Treasury stock, at cost; 5,852 shares in 2013 and 5,919 shares in 2012	(80,540)	(80,540)
Accumulated other comprehensive loss	(230)	(1,284)
Stockholders' Equity Attributable to Parent	341,862	290,364
Liabilities and Stockholders' Equity	$ 537,452	$ 467,737