Reportable Segment Information - Financial Information by Segment (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Sales	$ 594	$ 577	$ 569	$ 545	$ 547	$ 534	$ 514	$ 489	$ 2,285	$ 2,084	$ 1,929
Operating income	$ 105	$ 102	$ 100	$ 88	$ 113	$ 87	$ 100	$ 94	395	394	396
Depreciation and amortization									54	42	38
Equity income									14	12	12
Operating Segments
Segment Reporting Information [Line Items]
Operating income									409	405	403
Operating Segments | Core North America
Segment Reporting Information [Line Items]
Sales									1,035	1,004	979
Operating income									172	199	212
Depreciation and amortization									18	15	16
Operating Segments | Quick Lubes
Segment Reporting Information [Line Items]
Sales									660	541	457
Operating income									153	130	117
Depreciation and amortization									30	22	17
Operating Segments | International
Segment Reporting Information [Line Items]
Sales									590	539	493
Operating income									84	76	74
Depreciation and amortization									6	5	5
Unallocated and Other
Segment Reporting Information [Line Items]
Operating income									$ (14)	$ (11)	$ (7)