Shareholders' equity Repurchase of Common Shares (Details) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Feb. 26, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Jul. 01, 2023	May 19, 2022	Jul. 19, 2021
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased		7,518,565	11,825,600	14,925,028
2021 Stock Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased				14,925,028
Common Shares repurchased				$ 3,014
Stock repurchase program authorized amount							$ 5,000
2022 Stock Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased			11,825,600
Common Shares repurchased			$ 2,478
Stock repurchase program authorized amount						$ 2,500
July 2023 Stock Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased		7,518,565
Common Shares repurchased		$ 2,024
Stock repurchase program authorized amount					$ 5,000
Subsequent Event [Member] | July 2023 Stock Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased	543,782
Common Shares repurchased	$ 148