Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
ASSETS
Cash and cash equivalents	$ 442,021	$ 438,010
Marketable securities	3,200	13,255
Trade accounts receivable, net	629,370	577,522
Other accounts receivable	53,196	43,849
Operating supplies, at lower of average cost or market	25,674	22,822
Prepaid expenses	38,564	48,369
Deferred income taxes	17,069	46,563
Total Current Assets	1,209,094	1,190,390
Property, Plant and Equipment
Land	189,319	194,078
Buildings and leasehold improvements	829,231	827,910
Revenue equipment	1,709,507	1,613,806
Other equipment	328,304	318,313
Total Property, Plant and Equipment	3,056,361	2,954,107
Accumulated depreciation	(1,509,860)	(1,458,074)
Net Property, Plant and Equipment	1,546,501	1,496,033
Other Assets
Deferred charges and other assets	34,957	36,743
Capitalized software, net	20,941	19,829
Marketable securities	0	5,354
Intangible assets, net	11,586	13,951
Goodwill	338,041	337,716
Total Noncurrent Assets	405,525	413,593
Total Assets	3,161,120	3,100,016
LIABILITIES AND SHAREHOLDERS' EQUITY
Accounts payable	361,489	345,489
Accrued liabilities	255,472	235,146
Self-insurance accruals	104,272	104,328
Short-term borrowings	10,639	14,481
Current maturities of long-term debt and capital leases	12,745	24,026
Total Current Liabilities	744,617	723,470
Long-Term Liabilities
Long-term debt	718,983	718,336
Long-term obligations under capital leases	36,765	51,902
Self-insurance accruals	148,903	158,889
Employee benefits	555,070	610,850
Other liabilities and deferred credits	34,814	39,120
Deferred income taxes	71,581	38,195
Total Liabilities	2,310,733	2,340,762
Commitments and Contingencies (Note 8)
Shareholders' Equity
Common stock, $0.625 par value; authorized 100,000,000 shares; issued 63,550,965 and 63,065,931 shares, respectively	39,692	39,394
Additional paid-in capital, common stock	611,094	595,992
Retained earnings	955,141	884,758
Cost of repurchased common stock (7,581,970 and 7,468,869 shares, respectively)	(326,088)	(322,454)
Accumulated other comprehensive loss	(429,452)	(438,436)
Total Shareholders' Equity	850,387	759,254
Total Liabilities and Shareholders' Equity	$ 3,161,120	$ 3,100,016