CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
CURRENT ASSETS
Cash and cash equivalents	$ 107,611	$ 90,702
Short-term investments	28,573	29,054
Restricted cash, cash equivalents, and short-term investments	1,902	9,658
Accounts receivable, less allowances (2013 – $4,645; 2012 – $5,249)	212,946	180,631
Other accounts receivable, less allowances (2013 – $1,402; 2012 – $1,334)	9,532	6,539
Prepaid expenses	15,980	17,355
Deferred income taxes	47,038	39,245
Prepaid and refundable income taxes	2,186	5,681
Other	8,882	7,185
TOTAL CURRENT ASSETS	434,650	386,050
PROPERTY, PLANT AND EQUIPMENT
Land and structures	245,207	243,699
Revenue equipment	591,367	589,729
Service, office, and other equipment	122,057	119,456
Software	109,111	103,164
Leasehold improvements	23,524	23,272
PROPERTY, PLANT AND EQUIPMENT, GROSS	1,091,266	1,079,320
Less allowances for depreciation and amortization	691,730	635,292
PROPERTY, PLANT AND EQUIPMENT, NET	399,536	444,028
GOODWILL	76,448	73,189
INTANGIBLE ASSETS, net	76,431	79,561
OTHER ASSETS	51,058	51,634
TOTAL ASSETS	1,038,123	1,034,462
CURRENT LIABILITIES
Bank overdraft and drafts payable	11,645	13,645
Accounts payable	95,609	84,292
Income taxes payable	2,868	59
Accrued expenses	181,197	158,668
Current portion of long-term debt	35,353	43,044
TOTAL CURRENT LIABILITIES	326,672	299,708
LONG-TERM DEBT, less current portion	88,893	112,941
PENSION AND POSTRETIREMENT LIABILITIES	38,040	104,673
OTHER LIABILITIES	13,560	12,832
DEFERRED INCOME TAXES	71,275	45,309
STOCKHOLDERS' EQUITY
Common stock, $0.01 par value, authorized 70,000,000 shares; issued 2013: 27,408,046 shares; 2012: 27,296,285 shares	274	273
Additional paid-in capital	291,445	289,711
Retained earnings	287,204	284,157
Treasury stock, at cost, 1,677,932 shares	(57,770)	(57,770)
Accumulated other comprehensive loss	(21,470)	(57,372)
TOTAL STOCKHOLDERS' EQUITY	499,683	458,999
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 1,038,123	$ 1,034,462