Equity Items - Summary of Reconciliation of Changes in Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Balance, beginning of period		$ 3,406	$ 3,406
Balance, end of period		$ 3,571	$ 3,406	$ 3,406
Cash dividends declared per common share		$ 1.05	$ 0.95	$ 1.23
Common Stock and Paid in Capital [Member]
Balance, beginning of period		$ 947	$ 932	$ 924
Common shares issued under stock incentive and other plans	[1]	10	15	8
Common shares purchased under repurchase program	[2]	(200)
Balance, end of period		757	947	932
Retained earnings [Member]
Balance, beginning of period		2,750	2,696	2,704
Adoption of new accounting pronouncements	[3]	34
Net income (loss)		505	114	1
Regular dividends		(65)	(60)	(77)
Distribution of Valvoline Inc	[4]			68
Balance, end of period		3,224	2,750	2,696
Accumulated other comprehensive income (loss) [Member]
Balance, beginning of period		(291)	(222)	(281)
Adoption of new accounting pronouncements	[3]	(34)
Unrealized translation gain (loss)		(80)	(82)	81
Distribution of Valvoline Inc	[4]			(33)
Net change in investment securities			13	15
Pension and postretirement obligation adjustment		(5)		(4)
Balance, end of period		$ (410)	$ (291)	(222)
Noncontrolling Interest [Member]
Balance, beginning of period				(182)
Net income (loss)				27
Distribution of Valvoline Inc	[4]			152
Other				7
Distributions to noncontrolling interest				$ (4)

[1] Common shares issued were 336,188, 360,468 and 42,861 for 2019, 2018 and 2017, respectively

[2] Common shares repurchased were 2,637,054 for 2019

[3] Represents the cumulative-effect adjustment related to the adoption of the new guidance related to the accounting for equity securities and tax effects of intercompany transfers during fiscal 2019. See Note A for more information.

[4] See Note B for discussion of the noncontrolling interest and the initial public offering and distribution of Valvoline Inc