RESTRUCTURING - Schedule of Restructuring Charges (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Restructuring Cost and Reserve [Line Items]
Total Integration 2.0 restructuring charges	$ 8,000	$ 9,000
Freight Segment
Restructuring Cost and Reserve [Line Items]
Total Integration 2.0 restructuring charges	1,000	2,000
Transit Segment
Restructuring Cost and Reserve [Line Items]
Total Integration 2.0 restructuring charges	7,000	7,000
Cost of goods sold | Freight Segment
Restructuring Cost and Reserve [Line Items]
Total Integration 2.0 restructuring charges	1,000	1,000
Cost of goods sold | Transit Segment
Restructuring Cost and Reserve [Line Items]
Total Integration 2.0 restructuring charges	3,000	3,000
Selling, general and administrative expenses | Freight Segment
Restructuring Cost and Reserve [Line Items]
Total Integration 2.0 restructuring charges	0	1,000
Selling, general and administrative expenses | Transit Segment
Restructuring Cost and Reserve [Line Items]
Total Integration 2.0 restructuring charges	3,000	2,000
Amortization expense | Transit Segment
Restructuring Cost and Reserve [Line Items]
Total Integration 2.0 restructuring charges	$ 1,000	$ 2,000