Stockholders' Equity - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI beginning balance			$ (8,268)
Other comprehensive income (loss) before reclassifications	$ (410)	$ (1,518)	(1,853)	$ (345)
Amounts reclassified from AOCI into earnings	243	240	420	443
Other comprehensive income (loss), net of tax	(167)	(1,278)	(1,433)	98
AOCI ending balance	(9,701)		(9,701)
Securities Available for Sale
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI beginning balance	(7,613)	(6,714)	(6,769)	(7,676)
Other comprehensive income (loss) before reclassifications	(184)	(888)	(1,028)	74
Amounts reclassified from AOCI into earnings	0	0	0	0
Other comprehensive income (loss), net of tax	(184)	(888)	(1,028)	74
AOCI ending balance	(7,797)	(7,602)	(7,797)	(7,602)
Hedging relationships:
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI beginning balance	(1,903)	(1,781)	(1,493)	(2,182)
Other comprehensive income (loss) before reclassifications	(225)	(664)	(812)	(466)
Amounts reclassified from AOCI into earnings	243	240	420	443
Other comprehensive income (loss), net of tax	18	(424)	(392)	(23)
AOCI ending balance	(1,885)	(2,205)	(1,885)	(2,205)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI beginning balance	13	(7)	26	(20)
Other comprehensive income (loss) before reclassifications	(1)	34	(14)	47
Amounts reclassified from AOCI into earnings	0	0	0	0
Other comprehensive income (loss), net of tax	(1)	34	(14)	47
AOCI ending balance	12	27	12	27
Other:
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI beginning balance	(31)	(38)	(32)	(38)
Other comprehensive income (loss) before reclassifications	0	0	1	0
Amounts reclassified from AOCI into earnings	0	0	0	0
Other comprehensive income (loss), net of tax	0	0	1	0
AOCI ending balance	(31)	(38)	(31)	(38)
Total
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI beginning balance	(9,534)	(8,540)	(8,268)	(9,916)
AOCI ending balance	(9,701)	(9,818)	(9,701)	(9,818)
Net investment hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other comprehensive gain (loss)	$ 13	$ (78)	$ 62	$ (116)