Shareholders' equity Share Repurchases (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Apr. 25, 2024	Mar. 31, 2024	Mar. 31, 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			2,010,400
Cost of shares repurchased			$ 428
Repurchase authorization remaining at end of period			$ 1,193
July 2023 Stock Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount				$ 5,000
Number of shares repurchased		1,220,121
Cost of shares repurchased		$ 316
Repurchase authorization remaining at end of period		$ 3,373
Subsequent Event [Member] | July 2023 Stock Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased	250,000
Cost of shares repurchased	$ 62
Repurchase authorization remaining at end of period	$ 3,312