Accumulated other comprehensive loss - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at the beginning of the year	$ 21,116	$ 22,396	$ 21,288	$ 22,732
Other comprehensive income (loss) before reclassifications	354	(153)	159	5
Amounts reclassified from Accumulated other comprehensive loss	(6)	2	(27)	12
Other comprehensive income (loss)	(348)	151	(132)	(17)
Balance at the end of the year	22,805	22,328	22,805	22,328
Accumulated Other Comprehensive Loss
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at the beginning of the year	(813)	(625)	(616)	(787)
Other comprehensive income (loss)	(314)	138	(117)	(24)
Balance at the end of the year	(499)	(763)	(499)	(763)
Currency Translation
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at the beginning of the year	(617)	(605)	(439)	(746)
Balance at the end of the year	(288)	(722)	(288)	(722)
Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at the beginning of the year	(65)	5	(47)	(19)
Balance at the end of the year	(73)	(15)	(73)	(15)
Pension and Other Postretirement Plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at the beginning of the year	(131)	(25)	(130)	(22)
Balance at the end of the year	(138)	(26)	(138)	(26)
Noncontrolling Interests
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at the beginning of the year	390	575	434	575
Other comprehensive income (loss)	(34)	13	(15)	7
Balance at the end of the year	930	561	930	561
Accumulated foreign currency adjustment attributable to noncontrolling interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Other comprehensive income (loss)	(34)	13	(15)	7
Accumulated gain (loss), net, cash flow hedge, noncontrolling interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Other comprehensive income (loss)	0	0	0	0
Accumulated defined benefit plans adjustment attributable to noncontrolling interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Other comprehensive income (loss)	0	0	0	0
Accumulated foreign currency adjustment including portion attributable to noncontrolling interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Other comprehensive income (loss) before reclassifications	363	(130)	205	17
Amounts reclassified from Accumulated other comprehensive loss	0	0	(39)	0
Other comprehensive income (loss)	(363)	130	(166)	(17)
Cash flow hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Other comprehensive income (loss) before reclassifications	(9)	(23)	(46)	(12)
Amounts reclassified from Accumulated other comprehensive loss	1	3	20	16
Other comprehensive income (loss)	8	20	26	(4)
Pension and other postretirement plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from Accumulated other comprehensive loss	(7)	(1)	(8)	(4)
Other comprehensive income (loss)	$ 7	$ 1	$ 8	$ 4