Shareholders' Equity - Accumulated Other Comprehensive Income by Component (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 23,799	$ 25,191	$ 27,363
Other comprehensive income (loss) before reclassifications	(160)	775	(2,700)
Increase (decrease) due to amounts reclassified from accumulated other comprehensive income	414	582	122
Other comprehensive income (loss)	254	1,357	(2,578)
Ending balance	25,326	23,799	25,191
Unrecognized gain (loss) in AOCI	(374)	(530)	(749)
Net Unrealized Gains (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(131)	(359)	(2)
Other comprehensive income (loss) before reclassifications	39	75	(321)
Increase (decrease) due to amounts reclassified from accumulated other comprehensive income	(40)	153	(36)
Other comprehensive income (loss)	(1)	228	(357)
Ending balance	(132)	(131)	(359)
Net Unrealized Gains (Losses) on Investment Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(947)	(1,817)	(50)
Other comprehensive income (loss) before reclassifications	15	442	(1,937)
Increase (decrease) due to amounts reclassified from accumulated other comprehensive income	452	428	170
Other comprehensive income (loss)	467	870	(1,767)
Ending balance	(480)	(947)	(1,817)
Net Unrealized Losses on Retirement Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(145)	(143)	(130)
Other comprehensive income (loss) before reclassifications	14	(3)	(1)
Increase (decrease) due to amounts reclassified from accumulated other comprehensive income	2	1	(12)
Other comprehensive income (loss)	16	(2)	(13)
Ending balance	(129)	(145)	(143)
Foreign Currency Translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(1,400)	(1,751)	(1,019)
Other comprehensive income (loss) before reclassifications	(768)	351	(732)
Increase (decrease) due to amounts reclassified from accumulated other comprehensive income	0	0	0
Other comprehensive income (loss)	(768)	351	(732)
Ending balance	(2,168)	(1,400)	(1,751)
Net Unrealized Gains (Losses) on Hedges of Net Investments in Non-U.S. Subsidiaries
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	269	359	68
Other comprehensive income (loss) before reclassifications	540	(90)	291
Increase (decrease) due to amounts reclassified from accumulated other comprehensive income	0	0	0
Other comprehensive income (loss)	540	(90)	291
Ending balance	809	269	359
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2,354)	(3,711)	(1,133)
Other comprehensive income (loss)	254	1,357	(2,578)
Ending balance	$ (2,100)	$ (2,354)	$ (3,711)