Segment Information - Additional Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Sep. 30, 2018
Segment Reporting Information [Line Items]
Equity income (loss)	$ 62	$ 85	$ 145	$ 181
Depreciation	72	101	137	197
Capital Expenditures	108	123	252	266
Total Assets	10,574		10,574		$ 10,942
Operating segments | Americas
Segment Reporting Information [Line Items]
Equity income (loss)	0	2	1	3
Depreciation	27	36	51	70
Capital Expenditures	52	42	100	104
Total Assets	3,309		3,309
Operating segments | EMEA
Segment Reporting Information [Line Items]
Equity income (loss)	3	3	5	6
Depreciation	34	51	63	99
Capital Expenditures	46	67	130	147
Total Assets	2,806		2,806
Operating segments | Asia
Segment Reporting Information [Line Items]
Equity income (loss)	59	80	139	172
Depreciation	11	11	23	22
Capital Expenditures	10	14	22	15
Total Assets	3,653		3,653
Segment Reconciling Items
Segment Reporting Information [Line Items]
Equity income (loss)	0	0	0	0
Depreciation	0	3	0	6
Capital Expenditures	0	$ 0	0	$ 0
Total Assets	$ 806		$ 806