CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
CURRENT ASSETS
Cash and cash equivalents	$ 159,382	$ 105,354
Short-term investments	43,858	35,906
Restricted cash, cash equivalents, and short-term investments	1,385	1,902
Accounts receivable, less allowances (2014 - $5,613; 2013 - $4,533)	243,099	202,540
Other accounts receivable, less allowances (2014 - $1,676; 2013 - $1,422)	6,144	7,272
Prepaid expenses	17,542	19,016
Deferred income taxes	43,352	37,482
Prepaid and refundable income taxes	2,262	2,061
Other	7,489	6,952
TOTAL CURRENT ASSETS	524,513	418,485
PROPERTY, PLANT AND EQUIPMENT
Land and structures	250,816	245,805
Revenue equipment	629,791	589,902
Service, office, and other equipment	128,645	124,303
Software	113,770	110,998
Leasehold improvements	23,941	23,582
TOTAL PROPERTY, PLANT AND EQUIPMENT, GROSS	1,146,963	1,094,590
Less allowances for depreciation and amortization	735,090	700,193
PROPERTY, PLANT AND EQUIPMENT, net	411,873	394,397
GOODWILL	77,078	76,448
INTANGIBLE ASSETS, net	73,919	75,387
OTHER ASSETS	53,184	52,609
TOTAL ASSETS	1,140,567	1,017,326
CURRENT LIABILITIES
Bank overdraft and drafts payable	15,914	13,609
Accounts payable	135,022	89,091
Income taxes payable	16,809	1,782
Accrued expenses	187,682	173,622
Current portion of long-term debt	40,088	31,513
TOTAL CURRENT LIABILITIES	395,515	309,617
LONG-TERM DEBT, less current portion	85,735	81,332
PENSION AND POSTRETIREMENT LIABILITIES	37,272	26,847
OTHER LIABILITIES	14,482	15,041
DEFERRED INCOME TAXES	56,481	64,028
STOCKHOLDERS' EQUITY
Common stock, $0.01 par value, authorized 70,000,000 shares; issued 2014: 27,697,264 shares; 2013: 27,507,241 shares	277	275
Additional paid-in capital	301,365	296,133
Retained earnings	325,910	296,735
Treasury stock, at cost, 1,677,932 shares	(57,770)	(57,770)
Accumulated other comprehensive loss	(18,700)	(14,912)
TOTAL STOCKHOLDERS' EQUITY	551,082	520,461
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 1,140,567	$ 1,017,326