CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
CURRENT ASSETS
Cash and cash equivalents	$ 74,122	$ 127,444
Short-term investments	24,552	29,759
Accounts receivable, less allowances (2025 - $8,269; 2024 - $8,257)	414,133	394,838
Other accounts receivable, less allowances (2025 - $656; 2024 - $648)	25,027	36,055
Prepaid expenses	46,666	47,860
Prepaid and refundable income taxes	29,106	28,641
Other	11,557	11,045
TOTAL CURRENT ASSETS	625,163	675,642
PROPERTY, PLANT AND EQUIPMENT
Land and structures	530,957	520,119
Revenue equipment	1,160,332	1,166,161
Service, office, and other equipment	352,383	351,907
Software	185,526	182,396
Leasehold improvements	33,368	32,263
TOTAL PROPERTY, PLANT AND EQUIPMENT, Gross	2,262,566	2,252,846
Less allowances for depreciation and amortization	1,199,180	1,186,800
PROPERTY, PLANT AND EQUIPMENT, net	1,063,386	1,066,046
GOODWILL	304,753	304,753
INTANGIBLE ASSETS, net	85,449	88,615
OPERATING RIGHT-OF-USE ASSETS	228,684	192,753
DEFERRED INCOME TAXES	9,273	9,536
OTHER LONG-TERM ASSETS	90,176	92,386
TOTAL ASSETS	2,406,884	2,429,731
CURRENT LIABILITIES
Accounts payable	166,869	168,943
Accrued expenses	356,702	398,700
Current portion of long-term debt	66,692	63,978
Current portion of operating lease liabilities	34,080	34,364
TOTAL CURRENT LIABILITIES	624,343	665,985
LONG-TERM DEBT, less current portion	147,528	125,156
OPERATING LEASE LIABILITIES, less current portion	214,606	189,978
POSTRETIREMENT LIABILITIES, less current portion	13,378	13,361
DEFERRED INCOME TAXES	79,315	78,649
OTHER LONG-TERM LIABILITIES	32,970	42,240
STOCKHOLDERS' EQUITY
Common stock, $0.01 par value, authorized 70,000,000 shares; issued 2025: 30,402,056 shares; 2024: 30,401,768 shares	304	304
Additional paid-in capital	331,944	329,575
Retained earnings	1,435,596	1,435,250
Treasury stock, at cost, 2025: 7,373,609 shares; 2024: 7,114,844 shares	(473,029)	(451,039)
Accumulated other comprehensive income (loss)	(71)	272
TOTAL STOCKHOLDERS' EQUITY	1,294,744	1,314,362
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 2,406,884	$ 2,429,731