Equity and Noncontrolling Interests - Schedule of Changes in Redeemable Noncontrolling Interest (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance			$ 342
Dividends	$ (8)	$ (7)	(16)	$ (11)
Ending balance	340		340
Redeemable Noncontrolling Interest
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	41	42	240	43
Net income	9	7	22	13
Dividends	(2)	0	(33)	(14)
Change in redeemable noncontrolling interest	0	0	(186)	0
Foreign currency translation adjustments	0	(5)	5	2
Ending balance	$ 48	$ 44	$ 48	$ 44