Shareholders' equity Share Repurchases (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	May 01, 2023	Mar. 31, 2023	Mar. 31, 2022	May 19, 2022	Jul. 19, 2021
July 2021 Stock Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount					$ 5,000
Number of shares repurchased			4,869,900
Cost of shares repurchased			$ 1,001
Repurchase authorization remaining at end of period			$ 1,648
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
Subsequent Event [Member] | May 2022 Stock Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased	215,400
Cost of shares repurchased	$ 43
Repurchase authorization remaining at end of period	$ 1,150