Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 397	$ 236	$ 893	$ 427
Other comprehensive income (loss), net of tax
Foreign currency translation adjustments	63	(494)	371	(233)
Realized and unrealized gains (losses) on derivatives	8	(10)	9	(3)
Pension and postretirement plans	0	0	(1)	(1)
Other comprehensive income (loss)	71	(504)	379	(237)
Total comprehensive income (loss)	468	(268)	1,272	190
Comprehensive income attributable to noncontrolling interests	31	0	112	44
Comprehensive income (loss)	$ 437	$ (268)	$ 1,160	$ 146