REVENUE FROM CONTRACTS WITH CUSTOMERS - Remaining Performance Obligations (Details) $ in Billions	6 Months Ended
	Mar. 31, 2019 USD ($) M
REVENUE FROM CONTRACTS WITH CUSTOMERS
Revenue, Remaining Performance Obligation, Amount	$ 1.6
Revenue from Contracts with Customers
Number Of Months Of Unsatisfied Performance Obligations Represented In Backlog Contracts With Month To Month Terms | M	1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01
REVENUE FROM CONTRACTS WITH CUSTOMERS
Revenue, Remaining Performance Obligation, Amount	$ 0.7
Revenue from Contracts with Customers
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
REVENUE FROM CONTRACTS WITH CUSTOMERS
Revenue, Remaining Performance Obligation, Amount	$ 0.7
Revenue from Contracts with Customers
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
REVENUE FROM CONTRACTS WITH CUSTOMERS
Revenue, Remaining Performance Obligation, Amount	$ 0.2
Revenue from Contracts with Customers
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
REVENUE FROM CONTRACTS WITH CUSTOMERS
Revenue, Remaining Performance Obligation, Amount	$ 0.1
Revenue from Contracts with Customers
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period