LONG-TERM DEBT AND FINANCING ARRANGEMENTS - Assets Securing Notes (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Financing Arrangements
Total assets securing notes payable or held under finance leases	$ 345,046	$ 336,222
Less accumulated depreciation and amortization	130,896	119,244
Net assets securing notes payable or held under finance leases	214,150	216,978
Revenue equipment
Financing Arrangements
Total assets securing notes payable or held under finance leases	305,925	294,700
Service, office, and other equipment
Financing Arrangements
Total assets securing notes payable or held under finance leases	$ 39,121	$ 41,522