Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Assets
Cash and cash equivalents	$ 438,010	$ 421,420
Marketable securities	13,255
Trade accounts receivable, net	577,522	539,849
Other accounts receivable	43,849	79,065
Operating supplies, at lower of average cost or market	22,822	23,868
Prepaid expenses	48,369	47,345
Deferred income taxes	46,563	8,530
Total Current Assets	1,190,390	1,120,077
Property, Plant and Equipment
Land	194,078	194,818
Buildings and leasehold improvements	827,910	817,599
Revenue equipment	1,613,806	1,480,561
Other equipment	318,313	306,215
Total Property, Plant and Equipment	2,954,107	2,799,193
Accumulated depreciation	(1,458,074)	(1,394,608)
Net Property, Plant and Equipment	1,496,033	1,404,585
Other Assets
Deferred charges and other assets	36,743	39,107
Capitalized software, net	19,829	19,083
Marketable securities	5,354	6,039
Intangible assets, net	13,951	17,191
Goodwill	337,716	337,650
Total Noncurrent Assets	413,593	419,070
Total Assets	3,100,016	2,943,732
Liabilities and Shareholders' Equity
Accounts payable	345,489	304,176
Accrued liabilities	235,146	203,231
Self-insurance accruals	104,328	105,857
Short-term borrowings	14,481	18,552
Current maturities of long-term debt and capital leases	24,026	20,074
Total Current Liabilities	723,470	651,890
Long-Term Liabilities
Long-term debt	718,336	718,215
Long-term obligations under capital leases	51,902	75,735
Self-insurance accruals	158,889	169,311
Employee benefits	610,850	418,731
Other liabilities and deferred credits	39,120	41,789
Deferred income taxes	38,195	48,529
Total Liabilities	2,340,762	2,124,200
Commitments and Contingencies (Notes 6, 7, 8 and 12)
Shareholders' Equity
Common stock, $.625 par value; authorized 100,000,000 shares; issued 63,065,931 and 62,750,994 shares, respectively	39,394	39,143
Additional paid-in capital, common stock	595,992	580,008
Retained earnings	884,758	821,187
Cost of repurchased common stock (7,468,869 and 7,884,597 shares, respectively)	(322,454)	(340,912)
Accumulated Other Comprehensive Loss	(438,436)	(279,894)
Total Shareholders' Equity	759,254	819,532
Total Liabilities and Shareholders' Equity	$ 3,100,016	$ 2,943,732