Revenue Recognition - Contract Balances (Details) - USD ($) $ in Millions	Dec. 31, 2023	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Contract liabilities - current	$ 2,122	$ 1,996
Accounts receivable - net
Disaggregation of Revenue [Line Items]
Contract assets - current	2,170	2,370
Other noncurrent assets
Disaggregation of Revenue [Line Items]
Contract assets - noncurrent	4	12
Deferred revenue
Disaggregation of Revenue [Line Items]
Contract liabilities - current	2,122	1,996
Other noncurrent liabilities
Disaggregation of Revenue [Line Items]
Contract liabilities - noncurrent	$ 306	$ 297