REVENUE - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2020	Mar. 31, 2020	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Percentage of performance obligations recognized at a point in time (more than)		80.00%
Percentage of performance obligations recognized over time (less than)		20.00%
Net favorable (unfavorable) catch-up adjustments to income from operations	$ (2,224)	$ (5,243)
Accumulated estimated costs to complete loss contracts	$ 8,560	$ 8,560	$ 9,790