GOODWILL & OTHER INTANGIBLE ASSETS - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) segment	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Goodwill [Line Items]
Number of operating segments | segment	2
Goodwill	$ 188,407	$ 188,409	$ 188,434
Goodwill and intangible asset impairment	0
Transportation Solutions
Goodwill [Line Items]
Goodwill	120,484	120,486	120,502
Parts & Services
Goodwill [Line Items]
Goodwill	$ 67,923	$ 67,923	$ 67,932