Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
CURRENT ASSETS
Cash and cash equivalents	$ 52,171	$ 17,303
Trade receivables, net	73,744	77,034
Prepaid tires	9,424	10,160
Prepaid shop supplies	1,840	2,056
Other current assets	34,061	8,992
Income tax receivable	7,191	19,920
Deferred income taxes, net	16,855	14,767
Total current assets	195,286	150,232
PROPERTY AND EQUIPMENT
Land and land improvements	23,204	22,463
Buildings	34,963	34,151
Leasehold improvements	8,032	8,033
Furniture and fixtures	2,096	2,096
Shop and service equipment	10,875	10,820
Revenue equipment	575,861	600,335
Construction in progress	585	668
Property, Plant and Equipment, Gross	655,616	678,566
Less accumulated depreciation	197,306	198,007
Property and equipment, net	458,310	480,559
GOODWILL	100,212	100,212
OTHER INTANGIBLES, NET	15,754	16,380
OTHER ASSETS	10,953	12,611
Assets	780,515	759,994
CURRENT LIABILITIES
Accounts payable and accrued liabilities	33,918	8,261
Compensation and benefits	28,220	26,303
Insurance accruals	19,534	19,249
Other accruals	13,544	14,475
Total current liabilities	95,216	68,288
LONG-TERM LIABILITIES
Income taxes payable	17,257	18,296
Long-term debt	0	24,600
Deferred income taxes, net	102,169	101,605
Insurance accruals less current portion	60,729	59,300
Other long-term liabilities	12,418	11,318
Total long-term liabilities	192,573	215,119
COMMITMENTS AND CONTINGENCIES (Note 14)
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 2015 and 2014; outstanding 87,791 in 2015 and 87,781 in 2014, respectively	907	907
Additional paid-in capital	4,210	4,058
Retained earnings	525,686	509,834
Treasury stock, at cost; 2,898 shares in 2015 and 2,908 in 2014, respectively	(38,077)	(38,212)
Stockholders' Equity Attributable to Parent	492,726	476,587
Liabilities and Stockholders' Equity	$ 780,515	$ 759,994