Shareholders' equity AOCI Reclassifications (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Equity, Class of Treasury Stock [Line Items]
Income tax expense	$ (646)	$ (321)
Interest expense	198	181
Net income	2,347	1,343
Reclassification out of Accumulated Other Comprehensive Income
Equity, Class of Treasury Stock [Line Items]
Net income	(119)	24
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Including Noncontrolling Interest | Reclassification out of Accumulated Other Comprehensive Income
Equity, Class of Treasury Stock [Line Items]
Debt Securities, Available-for-Sale, Realized Gain (Loss)	(113)	(58)
Income tax expense	18	25
Net income	(95)	(33)
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest | Reclassification out of Accumulated Other Comprehensive Income
Equity, Class of Treasury Stock [Line Items]
Income tax expense	(2)	(2)
Interest expense	9	8
Net income	7	6
Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest | Reclassification out of Accumulated Other Comprehensive Income
Equity, Class of Treasury Stock [Line Items]
Income tax expense	8	(14)
Interest expense	(5)	(4)
Foreign Currency Transaction Gain (Loss), Realized	(34)	69
Net income	$ (31)	$ 51