Shareholders' equity Share Repurchases (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Jul. 01, 2023	May 19, 2022
May 2022 Stock Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount						$ 2,500
Number of shares repurchased				8,634,600
Cost of shares repurchased				$ 1,758
Repurchase authorization remaining at end of period		$ 4,398		4,398
July 2023 Stock Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount					$ 5,000
Number of shares repurchased	1,441,607	2,949,900	4,915,964
Cost of shares repurchased	$ 413	$ 606	$ 1,299
Repurchase authorization remaining at end of period	$ 2,400	$ 4,398	$ 2,400	$ 4,398