LEASES - Operating Lease Assets and Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2020	Oct. 01, 2019
Operating Leased Assets [Line Items]
Weighted-average remaining lease term (years)	5 years
Weighted-average discount rate	3.86%
Operating lease assets		$ 333
Operating lease liabilities	$ 351	$ 357
Other assets
Operating Leased Assets [Line Items]
Operating lease assets	327
Other payables
Operating Leased Assets [Line Items]
Operating lease liabilities	$ 351