Consolidated Balance Sheets (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
ASSETS
Cash and cash equivalents	$ 469,413	$ 421,420
Trade accounts receivable, net	629,126	539,849
Other accounts receivable	54,276	79,065
Operating supplies, at lower of average cost or market	25,807	23,868
Prepaid expenses	45,290	47,345
Deferred income taxes	18,592	8,530
Total Current Assets	1,242,504	1,120,077
Property, Plant and Equipment
Land	194,818	194,818
Buildings and leasehold improvements	819,966	817,599
Revenue equipment	1,532,935	1,480,561
Other equipment	311,912	306,215
Total Property, Plant and Equipment	2,859,631	2,799,193
Accumulated depreciation	(1,428,371)	(1,394,608)
Net Property, Plant and Equipment	1,431,260	1,404,585
Other Assets
Deferred charges and other assets	36,438	39,107
Capitalized software, net	18,772	19,083
Marketable securities	5,774	6,039
Intangible assets, net	15,630	17,191
Goodwill	338,073	337,650
Total Noncurrent Assets	414,687	419,070
Total Assets	3,088,451	2,943,732
LIABILITIES AND SHAREHOLDERS' EQUITY
Accounts payable	373,139	304,176
Accrued liabilities	227,665	203,231
Self-insurance accruals	101,856	105,857
Short-term borrowings	19,185	18,552
Current maturities of long-term debt and capital leases	20,397	20,074
Total Current Liabilities	742,242	651,890
Long-Term Liabilities
Long-term debt	718,274	718,215
Long-term obligations under capital leases	66,069	75,735
Self-insurance accruals	158,454	169,311
Employee benefits	401,944	418,731
Other liabilities and deferred credits	43,674	41,789
Deferred income taxes	86,781	48,529
Total Liabilities	2,217,438	2,124,200
Commitments and Contingencies (Note 10)
Shareholders' Equity
Common stock, $0.625 par value; authorized 100,000,000 shares; issued 62,995,517 and 62,750,994 shares, respectively	39,345	39,143
Additional paid-in capital, common stock	590,993	580,008
Retained earnings	838,208	821,187
Cost of repurchased common stock (7,466,906 and 7,884,597 shares, respectively)	(322,417)	(340,912)
Total Common Shareholders' Equity	1,146,129	1,099,426
Accumulated Other Comprehensive Loss	(275,116)	(279,894)
Total Shareholders' Equity	871,013	819,532
Total Liabilities and Shareholders' Equity	$ 3,088,451	$ 2,943,732