Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation Of Revenue [Line Items]
Sales	$ 644	$ 543	$ 1,759	$ 1,520
Life Sciences [Member]
Disaggregation Of Revenue [Line Items]
Sales	228	193	602	548
Life Sciences [Member] | North America [Member]
Disaggregation Of Revenue [Line Items]
Sales	70	60	185	171
Life Sciences [Member] | Europe [Member]
Disaggregation Of Revenue [Line Items]
Sales	76	63	197	177
Life Sciences [Member] | Asia Pacific [Member]
Disaggregation Of Revenue [Line Items]
Sales	61	52	159	146
Life Sciences [Member] | Latin America & Other [Member]
Disaggregation Of Revenue [Line Items]
Sales	21	18	61	54
Personal Care [Member]
Disaggregation Of Revenue [Line Items]
Sales	172	147	490	409
Personal Care [Member] | North America [Member]
Disaggregation Of Revenue [Line Items]
Sales	50	46	146	129
Personal Care [Member] | Europe [Member]
Disaggregation Of Revenue [Line Items]
Sales	69	59	194	162
Personal Care [Member] | Asia Pacific [Member]
Disaggregation Of Revenue [Line Items]
Sales	31	25	93	68
Personal Care [Member] | Latin America & Other [Member]
Disaggregation Of Revenue [Line Items]
Sales	22	17	57	50
Specialty Additives [Member]
Disaggregation Of Revenue [Line Items]
Sales	194	169	532	474
Specialty Additives [Member] | North America [Member]
Disaggregation Of Revenue [Line Items]
Sales	71	53	185	146
Specialty Additives [Member] | Europe [Member]
Disaggregation Of Revenue [Line Items]
Sales	67	65	192	179
Specialty Additives [Member] | Asia Pacific [Member]
Disaggregation Of Revenue [Line Items]
Sales	48	43	133	123
Specialty Additives [Member] | Latin America & Other [Member]
Disaggregation Of Revenue [Line Items]
Sales	8	8	22	26
Intermediates [Member]
Disaggregation Of Revenue [Line Items]
Sales	73	49	192	118
Intermediates [Member] | North America [Member]
Disaggregation Of Revenue [Line Items]
Sales	47	33	121	73
Intermediates [Member] | Europe [Member]
Disaggregation Of Revenue [Line Items]
Sales	13	7	32	19
Intermediates [Member] | Asia Pacific [Member]
Disaggregation Of Revenue [Line Items]
Sales	10	7	31	21
Intermediates [Member] | Latin America & Other [Member]
Disaggregation Of Revenue [Line Items]
Sales	$ 3	$ 2	$ 8	$ 5