Guarantor Financial Information - Condensed Consolidating Statements of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Net Income (Loss) Attributable to Parent [Abstract]
Sales	$ 607	$ 557
Cost of sales	396	374
Gross profit	211	183
Selling, general and administrative expenses	117	105
Net legacy and separation-related income	(1)
Equity and other (income) expenses, net	(9)	(9)
Operating income	104	87
Net pension and other postretirement plan income	(9)	(2)
Net interest and other financing expenses	16	17
Income before income taxes	97	72
Income tax (benefit) expense	24	19
Equity in net income of subsidiaries	0	0
Net income	73	53
Comprehensive income	79	47
Eliminations
Net Income (Loss) Attributable to Parent [Abstract]
Sales	(13)	(15)
Cost of sales	(13)	(15)
Gross profit	0	0
Selling, general and administrative expenses	0	0
Net legacy and separation-related income	0
Equity and other (income) expenses, net	0	0
Operating income	0	0
Net pension and other postretirement plan income	0	0
Net interest and other financing expenses	0	0
Income before income taxes	0	0
Income tax (benefit) expense	0	0
Equity in net income of subsidiaries	93	72
Net income	(93)	(72)
Comprehensive income	(104)	(62)
Valvoline Inc. (Parent Issuer) | Reportable Legal Entities
Net Income (Loss) Attributable to Parent [Abstract]
Sales	0	0
Cost of sales	0	0
Gross profit	0	0
Selling, general and administrative expenses	4	3
Net legacy and separation-related income	(1)
Equity and other (income) expenses, net	0	0
Operating income	(3)	(3)
Net pension and other postretirement plan income	0	0
Net interest and other financing expenses	15	15
Income before income taxes	(18)	(18)
Income tax (benefit) expense	(6)	(5)
Equity in net income of subsidiaries	(85)	(66)
Net income	73	53
Comprehensive income	79	47
Guarantor Subsidiaries | Reportable Legal Entities
Net Income (Loss) Attributable to Parent [Abstract]
Sales	480	440
Cost of sales	309	293
Gross profit	171	147
Selling, general and administrative expenses	88	81
Net legacy and separation-related income	0
Equity and other (income) expenses, net	(13)	(13)
Operating income	96	79
Net pension and other postretirement plan income	(9)	(2)
Net interest and other financing expenses	1	1
Income before income taxes	104	80
Income tax (benefit) expense	27	20
Equity in net income of subsidiaries	(8)	(6)
Net income	85	66
Comprehensive income	89	60
Non-Guarantor Subsidiaries | Reportable Legal Entities
Net Income (Loss) Attributable to Parent [Abstract]
Sales	140	132
Cost of sales	100	96
Gross profit	40	36
Selling, general and administrative expenses	25	21
Net legacy and separation-related income	0
Equity and other (income) expenses, net	4	4
Operating income	11	11
Net pension and other postretirement plan income	0	0
Net interest and other financing expenses	0	1
Income before income taxes	11	10
Income tax (benefit) expense	3	4
Equity in net income of subsidiaries	0	0
Net income	8	6
Comprehensive income	$ 15	$ 2