INCOME TAXES - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Income Tax [Line Items]
Subsidiary, ownership percentage		100.00%
Estimated tax expense for refinement of tax reform items		$ 87,000,000	$ 89,000,000
Undistributed earnings in foreign subsidiaries on which income taxes have not been provided		0	1,163,000,000
Gross unrecognized tax benefits	$ 261,000,000	276,000,000	261,000,000	$ 269,000,000	$ 243,000,000
Unrecognized tax benefits that would impact effective tax rate		230,000,000
Interest on uncertain tax positions accrued	13,000,000	12,000,000	13,000,000
Penalties on uncertain tax positions accrued	1,000,000	1,000,000	1,000,000
Income tax penalties and interest expense		$ 1,000,000	$ 4,000,000	$ 5,000,000
Brazil
Income Tax [Line Items]
Non-cash income tax benefit for the reversal of valuation allowances	$ 9,000,000