Reportable Segment Information - Sales and Operating Income by Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Sales	$ 578	$ 591	$ 1,185	$ 1,148
Operating income	117	96	221	183
Operating Segments
Segment Reporting Information [Line Items]
Operating income	105	107	209	194
Unallocated and Other
Segment Reporting Information [Line Items]
Operating income	12	(11)	12	(11)
Quick Lubes
Segment Reporting Information [Line Items]
Sales	212	200	430	389
Quick Lubes | Operating Segments
Segment Reporting Information [Line Items]
Sales	212	200	430	389
Operating income	40	44	78	82
Core North America
Segment Reporting Information [Line Items]
Sales	238	243	486	475
Core North America | Operating Segments
Segment Reporting Information [Line Items]
Sales	238	243	486	475
Operating income	47	40	93	71
International
Segment Reporting Information [Line Items]
Sales	128	148	269	284
International | Operating Segments
Segment Reporting Information [Line Items]
Sales	128	148	269	284
Operating income	$ 18	$ 23	$ 38	$ 41