Guarantor Financial Information - Condensed Consolidating Statements of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Net Income (Loss) Attributable to Parent [Abstract]
Sales	$ 629	$ 613	$ 591	$ 557	$ 594	$ 577	$ 569	$ 545	$ 2,390	$ 2,285	$ 2,084
Cost of sales									1,580	1,479	1,308
Gross profit	217	207	203	183	203	201	207	195	810	806	776
Selling, general and administrative expenses									449	430	396
Net legacy and separation-related expenses									3	14	11
Equity and other income, net									(40)	(33)	(25)
Operating income	113	102	96	87	105	102	100	88	398	395	394
Net pension and other postretirement plan expense (income)	(69)				(38)				60	0	(138)
Net interest and other financing expenses									73	63	42
Income before income taxes									265	332	490
Income tax expense			(2)		2	3	2	71	57	166	186
Equity in net income of subsidiaries									0	0	0
Net income	$ 27	$ 65	$ 63	$ 53	$ 45	$ 64	$ 67	$ (10)	208	166	304
Total comprehensive income									187	147	303
Eliminations
Net Income (Loss) Attributable to Parent [Abstract]
Sales									(63)	(55)	(57)
Cost of sales									(63)	(55)	(57)
Gross profit									0	0	0
Selling, general and administrative expenses									0	0	0
Net legacy and separation-related expenses									0	0	0
Equity and other income, net									0	0	0
Operating income									0	0	0
Net pension and other postretirement plan expense (income)									0	0	0
Net interest and other financing expenses									0	0	0
Income before income taxes									0	0	0
Income tax expense									0	0	0
Equity in net income of subsidiaries									282	284	363
Net income									(282)	(284)	(363)
Total comprehensive income									(249)	(259)	373
Valvoline Inc. (Parent Issuer) | Reportable Legal Entities
Net Income (Loss) Attributable to Parent [Abstract]
Sales									0	0	0
Cost of sales									0	0	0
Gross profit									0	0	0
Selling, general and administrative expenses									10	11	9
Net legacy and separation-related expenses									2	8	(15)
Equity and other income, net									0	0	0
Operating income									(12)	(19)	6
Net pension and other postretirement plan expense (income)									0	0	0
Net interest and other financing expenses									63	53	36
Income before income taxes									(75)	(72)	(30)
Income tax expense									(31)	14	(3)
Equity in net income of subsidiaries									(252)	(252)	(331)
Net income									208	166	304
Total comprehensive income									187	147	303
Guarantor Subsidiaries | Reportable Legal Entities
Net Income (Loss) Attributable to Parent [Abstract]
Sales									1,896	1,782	1,618
Cost of sales									1,241	1,132	986
Gross profit									655	650	632
Selling, general and administrative expenses									348	327	296
Net legacy and separation-related expenses									1	6	26
Equity and other income, net									(57)	(50)	(37)
Operating income									363	367	347
Net pension and other postretirement plan expense (income)									57	1	(134)
Net interest and other financing expenses									7	6	4
Income before income taxes									299	360	477
Income tax expense									77	140	178
Equity in net income of subsidiaries									(30)	(32)	(32)
Net income									252	252	331
Total comprehensive income									231	234	330
Non-Guarantor Subsidiaries | Reportable Legal Entities
Net Income (Loss) Attributable to Parent [Abstract]
Sales									557	558	523
Cost of sales									402	402	379
Gross profit									155	156	144
Selling, general and administrative expenses									91	92	91
Net legacy and separation-related expenses									0	0	0
Equity and other income, net									17	17	12
Operating income									47	47	41
Net pension and other postretirement plan expense (income)									3	(1)	(4)
Net interest and other financing expenses									3	4	2
Income before income taxes									41	44	43
Income tax expense									11	12	11
Equity in net income of subsidiaries									0	0	0
Net income									30	32	32
Total comprehensive income									$ 18	$ 25	$ 43