Related Party Transactions - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Sep. 30, 2016
Related Party Transaction [Line Items]
Stock based compensation expense	$ 2,000,000	$ 2,000,000	$ 3,000,000	$ 5,000,000
General corporate expenses allocated to Valvoline	0	$ 20,000,000	0	$ 41,000,000
Hedging instrument | Fair value | Foreign currency derivative
Related Party Transaction [Line Items]
Notional amount of derivatives	30,000,000		30,000,000
Ashland
Related Party Transaction [Line Items]
Accounts receivable sold by Ashland to the financial institution	0		0		$ 29,000,000
Obligations to related party					73,000,000
Ashland | Interim tax-sharing payments, transition services and other miscellaneous billings
Related Party Transaction [Line Items]
Related party payments			60,000,000
Ashland | Payments from parent company
Related Party Transaction [Line Items]
Payments from related party			23,000,000
Ashland | Other current assets
Related Party Transaction [Line Items]
Receivables from related party	10,000,000		10,000,000		30,000,000
Ashland | Accrued expenses and other liabilities
Related Party Transaction [Line Items]
Obligations to related party	9,000,000		9,000,000		2,000,000
Ashland | Other long-term liabilities
Related Party Transaction [Line Items]
Obligations to related party	$ 79,000,000		$ 79,000,000		$ 71,000,000