Revenue Recognition - Reconciliation of Contract Balances (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023	Dec. 31, 2022
Reconciliation of Contract Balances
Notes and accounts receivable — trade (net of allowances of $198 in 2023 and $233 in 2022)	$ 5,330	$ 5,330	$ 6,541
Notes and accounts receivable - trade, allowances	198	198	233
Contract assets	454	454	464
Deferred income (current)	11,917	11,917	12,032
Deferred income (noncurrent)	3,085	3,085	$ 3,499
Revenue recognized that was included in deferred income at the beginning of the period	$ 4,300	$ 9,000