REVENUES (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2019	Mar. 31, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 436,100	$ 436,100
Percentage of Revenue Expected to be Recognized in Next Twelve Months	83.00%
Contract with Customer, Asset, Net	$ 87,000	87,000
Contract with Customer, Liability	51,000	51,000
Contract with Customer, Liability, Revenue Recognized		30,000
Contract with Customer, Asset, Net, Current	100,540	100,540	$ 53,034
Contract with Customer, Liability, Current	$ 55,453	$ 55,453	$ 49,035