Shareholders' equity AOCI Reclassifications (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Equity, Class of Treasury Stock [Line Items]
Interest expense	$ 181	$ 178
Income Tax (Expense) Benefit	(321)	(342)
Net income	1,343	2,294
Net income (loss)	1,331	2,143
Reclassification out of Accumulated Other Comprehensive Income
Equity, Class of Treasury Stock [Line Items]
Net income	24	(137)
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]
Income Tax (Expense) Benefit	25	12
Net income	(33)	(107)
Debt Securities, Available-for-Sale, Realized Gain (Loss)	(58)	(119)
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest | Reclassification out of Accumulated Other Comprehensive Income
Equity, Class of Treasury Stock [Line Items]
Interest expense	8	3
Income Tax (Expense) Benefit	(2)	(1)
Net income	6	2
Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest | Reclassification out of Accumulated Other Comprehensive Income
Equity, Class of Treasury Stock [Line Items]
Foreign Currency Transaction Gain (Loss), Realized	69	(37)
Interest expense	(4)	(4)
Income Tax (Expense) Benefit	(14)	9
Net income	$ 51	$ (32)