Equity and Noncontrolling Interests - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021
Foreign currency translation adjustments
Balance at beginning of period		$ (421)	$ (778)
Aggregate adjustment for the period		84	272
Aggregate adjustment for period, tax effect		0	0
Balance at end of period		(337)	(506)
Realized and unrealized gains (losses) on derivatives
Balance at beginning of period		(17)	2
Current period change in fair value		4	2
Current period change in fair value, Tax		3	2
Reclassification to income	[1]	0	(1)
Reclassifcation to income, tax effect		0	0
Balance at end of period		(13)	3
Pension and postretirement plans
Balance at beginning of period		4	0
Reclassification to income		(1)	(1)
Reclassification to income, tax effect		0	0
Balance at end of period		3	(1)
Accumulated other comprehensive loss		$ (347)	$ (504)	$ (434)

[1] Refer to Note 11, "Derivative Instruments and Hedging Activities," of the notes to consolidated financial statements for disclosure of the line items in the consolidated statements of income affected by reclassifications from AOCI into income related to derivatives.