Revenue Recognition Contract Assets (Liabilities) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2023	Jun. 30, 2023	Sep. 30, 2022
Revenue from Contract with Customer [Abstract]
Unbilled receivables (contract assets)	$ 1,385	$ 1,385	$ 1,390
Customer advances (contract liabilities)	(985)	(985)	(776)
Net contract liabilities	400	400	$ 614
Revenue recognized, included in beginning contract liability	59	500
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Backlog	$ 8,200	$ 8,200