FINANCIAL INSTRUMENTS - Changes in Fair Value of Level 3 Financial Assets and Liabilities (Details) - Level 3 - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair Value, beginning balance	$ 2	$ 2
Purchases, issuances, sales and settlements:
Purchases	2	1
Settlements	(3)	2
Transfer in and / or out of Level 3	0	0
Reclass between short-term and long-term	0	0
Fair Value, ending balance	3	2
Foreign Currency Option Contracts | Other Current Assets
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair Value, beginning balance	0	1
Purchases, issuances, sales and settlements:
Purchases	1	1
Settlements	(2)	0
Transfer in and / or out of Level 3	0	0
Reclass between short-term and long-term	3	0
Fair Value, ending balance	2	0
Foreign Currency Option Contracts | Other Noncurrent Assets
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair Value, beginning balance	2	1
Purchases, issuances, sales and settlements:
Purchases	1	0
Settlements	(1)	2
Transfer in and / or out of Level 3	0	0
Reclass between short-term and long-term	(3)	0
Fair Value, ending balance	1	2
Other Income
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Total unrealized gains (losses)	0	(2)
Total realized gains (losses)	0	0
Other Income | Foreign Currency Option Contracts | Other Current Assets
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Total unrealized gains (losses)	0	(2)
Total realized gains (losses)	0	0
Other Income | Foreign Currency Option Contracts | Other Noncurrent Assets
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Total unrealized gains (losses)	0	0
Total realized gains (losses)	0	0
Cost of Sales
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Total unrealized gains (losses)	2	(1)
Total realized gains (losses)	0	0
Cost of Sales | Foreign Currency Option Contracts | Other Current Assets
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Total unrealized gains (losses)	0	0
Total realized gains (losses)	0	0
Cost of Sales | Foreign Currency Option Contracts | Other Noncurrent Assets
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Total unrealized gains (losses)	2	(1)
Total realized gains (losses)	$ 0	$ 0