Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Disaggregation Of Revenue [Line Items]
Sales	$ 603	$ 604	$ 1,128	$ 1,115
Life Sciences [Member]
Disaggregation Of Revenue [Line Items]
Sales	240	204	447	374
Life Sciences [Member] | North America [Member]
Disaggregation Of Revenue [Line Items]
Sales	61	62	109	115
Life Sciences [Member] | Europe [Member]
Disaggregation Of Revenue [Line Items]
Sales	87	66	160	121
Life Sciences [Member] | Asia Pacific [Member]
Disaggregation Of Revenue [Line Items]
Sales	62	52	122	98
Life Sciences [Member] | Latin America & Other [Member]
Disaggregation Of Revenue [Line Items]
Sales	30	24	56	40
Personal Care [Member]
Disaggregation Of Revenue [Line Items]
Sales	167	172	305	318
Personal Care [Member] | North America [Member]
Disaggregation Of Revenue [Line Items]
Sales	48	55	90	96
Personal Care [Member] | Europe [Member]
Disaggregation Of Revenue [Line Items]
Sales	69	69	120	125
Personal Care [Member] | Asia Pacific [Member]
Disaggregation Of Revenue [Line Items]
Sales	28	30	56	62
Personal Care [Member] | Latin America & Other [Member]
Disaggregation Of Revenue [Line Items]
Sales	22	18	39	35
Specialty Additives [Member]
Disaggregation Of Revenue [Line Items]
Sales	161	182	304	338
Specialty Additives [Member] | North America [Member]
Disaggregation Of Revenue [Line Items]
Sales	52	61	105	114
Specialty Additives [Member] | Europe [Member]
Disaggregation Of Revenue [Line Items]
Sales	61	69	109	125
Specialty Additives [Member] | Asia Pacific [Member]
Disaggregation Of Revenue [Line Items]
Sales	39	45	74	85
Specialty Additives [Member] | Latin America & Other [Member]
Disaggregation Of Revenue [Line Items]
Sales	9	7	16	14
Intermediates [Member]
Disaggregation Of Revenue [Line Items]
Sales	51	66	105	119
Intermediates [Member] | North America [Member]
Disaggregation Of Revenue [Line Items]
Sales	36	43	70	74
Intermediates [Member] | Europe [Member]
Disaggregation Of Revenue [Line Items]
Sales	7	10	16	19
Intermediates [Member] | Asia Pacific [Member]
Disaggregation Of Revenue [Line Items]
Sales	6	11	14	21
Intermediates [Member] | Latin America & Other [Member]
Disaggregation Of Revenue [Line Items]
Sales	$ 2	$ 2	$ 5	$ 5