Consolidated Condensed Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Operations:
Net income	$ 10,289	$ 9,050
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation	27,600	25,649
Gain on disposition of revenue equipment	(1,735)	(628)
Deferred income taxes	7,274	(1,691)
Tax benefits from share-based payment arrangement exercises	164	273
Excess tax benefits from share-based payment arrangement exercises	(142)	(235)
Share-based payment arrangement compensation expense	595	460
Income before income taxes attributable to noncontrolling interest	390	57
Changes in other current operating items:
Receivables	(5,328)	(9,529)
Prepaid expenses and other	663	1,450
Accounts payable and accrued liabilities	5,203	115
Insurance and claims accruals	(2,517)	(1,003)
Net cash provided by operating activities	42,456	23,968
CASH FLOWS USED FOR INVESTING ACTIVITIES:
Other	120	(9)
Net cash used for investing activities	(11,879)	(37,487)
CASH FLOWS (USED FOR) PROVIDED BY FINANCING ACTIVITIES:
Borrowings under credit facility and long-term debt	35,382	69,650
Repayment of borrowings under credit facility and long-term debt	(54,728)	(57,628)
Dividends on common stock	(878)
Issuance of common stock from share-based payment arrangement exercises	137	234
Excess tax benefits from share-based payment arrangement exercises	142	235
Change in net checks issued in excess of cash balances	(1,066)	(978)
Noncontrolling interest distributions and other, net	131	159
Net cash (used for) provided by financing activities	(20,880)	11,672
NET CHANGE IN CASH AND CASH EQUIVALENTS	9,697	(1,847)
CASH AND CASH EQUIVALENTS:
Beginning of period	5,306	5,410
End of period	15,003	3,563
Cash paid (received) for:
Interest	32	115
Income taxes	(7,894)	9,736
Change in property and equipment not yet paid for	1,010	4,055
Revenue Equipment [Member]
CASH FLOWS USED FOR INVESTING ACTIVITIES:
Additions to property, plant, and equipment	(23,143)	(55,470)
Revenue Equipment [Member]
CASH FLOWS USED FOR INVESTING ACTIVITIES:
Proceeds from disposition of property, plant, and equipment	16,967	24,052
Buildings And Land Office Equipment And Other [Member]
CASH FLOWS USED FOR INVESTING ACTIVITIES:
Additions to property, plant, and equipment	(5,896)	(6,146)
Buildings And Land Office Equipment And Other [Member]
CASH FLOWS USED FOR INVESTING ACTIVITIES:
Proceeds from disposition of property, plant, and equipment	$ 73	$ 86