Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
CURRENT ASSETS
Cash and cash equivalents	$ 210,739	$ 139,770
Trade receivables, net	49,825	44,198
Prepaid tires	9,538	12,820
Other current assets	5,673	1,932
Income tax receivable	1,726	314
Deferred income taxes, net	13,532	14,401
Total current assets	291,033	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	7,267	7,324
Revenue equipment	349,107	355,905
Property, Plant and Equipment, Gross	402,855	409,710
Less accumulated depreciation	176,325	161,269
Property and equipment, net	226,530	248,441
LONG-TERM INVESTMENTS	21,041	50,569
GOODWILL	4,815	4,815
OTHER ASSETS	8,303	8,406
Assets	551,722	525,666
CURRENT LIABILITIES
Accounts payable and accrued liabilities	12,561	9,088
Compensation and benefits	16,781	15,493
Insurance accruals	13,686	13,997
Other accruals	8,076	7,085
Total current liabilities	51,104	45,663
LONG-TERM LIABILITIES
Income taxes payable	21,267	24,077
Deferred income taxes, net	52,291	57,661
Insurance accruals less current portion	56,502	57,494
Total long-term liabilities	130,060	139,232
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 2012 and 2011, outstanding, 86,475 in 2012 and 2011, respectively	907	907
Additional paid-in capital	2,220	589
Retained earnings	430,049	398,706
Treasury stock, at cost; 4,214 shares in 2012 and 2011	(61,334)	(56,350)
Accumulated other comprehensive loss	(1,284)	(3,081)
Stockholders' Equity Attributable to Parent	370,558	340,771
Liabilities and Stockholders' Equity	$ 551,722	$ 525,666