Financial Instruments - Narrative (Details) $ / shares in Units, $ in Millions, € in Billions	12 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Apr. 12, 2023 $ / shares	Sep. 30, 2019 EUR (€)
Derivative [Line Items]
Mark-to-market gain	$ 24	$ (50)
Fair value of notes receivable compared with carrying value, higher (lower)	(200)
National Instruments
Derivative [Line Items]
Business acquisition, purchase price per share (in dollars per share) | $ / shares			$ 60
National Instruments
Derivative [Line Items]
Investments	136
Mark-to-market gain	56
Level 2
Derivative [Line Items]
Fair value of notes receivable	1,900
Fair value of long-term debt	6,900	7,600
Fair value of long term debt compared with carrying value, higher (lower)	(1,275)	$ 1,207
Senior Notes
Derivative [Line Items]
Debt, face amount | €				€ 1.5
Foreign currency
Derivative [Line Items]
Notional value of hedge positions	$ 2,400