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Shareholders' equity Share Repurchases (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 24, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Jul. 01, 2025	Jul. 01, 2023
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	8,121,824	4,915,964
Cost of shares repurchased			$ 413	$ 2,293	$ 1,299
Repurchase authorization remaining at end of period		$ 3,783	$ 2,400	3,783	$ 2,400
July 2025 Stock Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount						$ 5,000
Number of shares repurchased		4,436,315
Cost of shares repurchased		$ 1,232
Repurchase authorization remaining at end of period		$ 3,783		$ 3,783
July 2025 Stock Repurchase Plan \| Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased	1,000,000
Cost of shares repurchased	$ 282
Repurchase authorization remaining at end of period	$ 3,502