Guarantor Financial Information - Condensed Consolidating Statements of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Net Income (Loss) Attributable to Parent [Abstract]
Sales	$ 569	$ 514	$ 1,114	$ 1,003
Cost of sales	362	316	712	620
Gross profit	207	198	402	383
Selling, general and administrative expenses	111	97	218	192
Legacy and separation-related expenses, net	8	6	17	12
Equity and other (income) expenses	(12)	(5)	(21)	(15)
Operating income	100	100	188	194
Net pension and other postretirement plan non-service income and remeasurement adjustments	(10)	(17)	(20)	(43)
Net interest and other financing expenses	16	8	30	18
(Loss) income before income taxes	94	109	178	219
Income tax expense	27	38	121	76
Equity in net income of subsidiaries	0	0	0	0
Net income	67	71	57	143
Comprehensive income	68	75	57	136
Eliminations
Net Income (Loss) Attributable to Parent [Abstract]
Sales	(14)	(15)	(25)	(27)
Cost of sales	(14)	(15)	(25)	(27)
Gross profit	0	0	0	0
Selling, general and administrative expenses	0	0	0	0
Legacy and separation-related expenses, net	0	0	0	0
Equity and other (income) expenses	0	0	0	0
Operating income	0	0	0	0
Net pension and other postretirement plan non-service income and remeasurement adjustments	0	0	0	0
Net interest and other financing expenses	0	0	0	0
(Loss) income before income taxes	0	0	0	0
Income tax expense	0	0	0	0
Equity in net income of subsidiaries	92	86	132	166
Net income	(92)	(86)	(132)	(166)
Comprehensive income	(95)	(96)	(135)	(157)
Valvoline Inc. (Parent Issuer) | Reportable Legal Entities
Net Income (Loss) Attributable to Parent [Abstract]
Sales	0	0	0	0
Cost of sales	0	0	0	0
Gross profit	0	0	0	0
Selling, general and administrative expenses	3	2	7	4
Legacy and separation-related expenses, net	1	0	7	0
Equity and other (income) expenses	0	0	0	0
Operating income	(4)	(2)	(14)	(4)
Net pension and other postretirement plan non-service income and remeasurement adjustments	0	0	0	0
Net interest and other financing expenses	13	8	25	17
(Loss) income before income taxes	(17)	(10)	(39)	(21)
Income tax expense	(4)	(4)	17	(8)
Equity in net income of subsidiaries	(80)	(77)	(113)	(156)
Net income	67	71	57	143
Comprehensive income	68	75	57	136
Guarantor Subsidiaries | Reportable Legal Entities
Net Income (Loss) Attributable to Parent [Abstract]
Sales	441	402	863	779
Cost of sales	275	241	538	465
Gross profit	166	161	325	314
Selling, general and administrative expenses	85	72	166	141
Legacy and separation-related expenses, net	7	6	10	12
Equity and other (income) expenses	(14)	(8)	(26)	(21)
Operating income	88	91	175	182
Net pension and other postretirement plan non-service income and remeasurement adjustments	(10)	(17)	(20)	(43)
Net interest and other financing expenses	2	0	3	1
(Loss) income before income taxes	96	108	192	224
Income tax expense	28	40	98	78
Equity in net income of subsidiaries	(12)	(9)	(19)	(10)
Net income	80	77	113	156
Comprehensive income	80	81	113	149
Non-Guarantor Subsidiaries | Reportable Legal Entities
Net Income (Loss) Attributable to Parent [Abstract]
Sales	142	127	276	251
Cost of sales	101	90	199	182
Gross profit	41	37	77	69
Selling, general and administrative expenses	23	23	45	47
Legacy and separation-related expenses, net	0	0	0	0
Equity and other (income) expenses	2	3	5	6
Operating income	16	11	27	16
Net pension and other postretirement plan non-service income and remeasurement adjustments	0	0	0	0
Net interest and other financing expenses	1	0	2	0
(Loss) income before income taxes	15	11	25	16
Income tax expense	3	2	6	6
Equity in net income of subsidiaries	0	0	0	0
Net income	12	9	19	10
Comprehensive income	$ 15	$ 15	$ 22	$ 8