Stockholders' Equity - Reclassifications from AOCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income	$ 6,517	$ 5,743	$ 12,914	$ 11,565
Interest expense	578	396	965	835
Non-interest income (loss)	99	231	442	353
Income from continuing operations before income taxes	2,564	4,568	5,509	8,764
Income tax provision (benefit)	533	1,031	1,075	1,900
Net income	2,031	3,536	4,434	6,861
Accumulated other comprehensive income (loss)	(6,916)		(6,916)			$ 374
Other comprehensive income (loss), net of tax	(2,823)	9	(7,290)	(1,702)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	66	244	152	491
Securities available for sale | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Non-interest income (loss)	(6)	0	(6)	4
Income tax provision (benefit)	(1)	0	(1)	1
Net income	(5)	0	(5)	3
Hedging Relationships
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss)	(1,574)	730	(1,574)	730	$ (1,091)	118	$ 781	$ 1,362
Other comprehensive income (loss) before reclassifications	(412)	193	(1,535)	(145)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(71)	(244)	(157)	(487)
Other comprehensive income (loss), net of tax	(483)	(51)	(1,692)	(632)
Hedging Relationships | Interest rate contracts | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income	63	245	190	480
Hedging Relationships | Foreign exchange contracts | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income	(1)	0	(1)	1
Interest expense	0	(1)	(1)	(2)
Non-interest income (loss)	31	77	18	162
Income from continuing operations before income taxes	93	321	206	641
Income tax provision (benefit)	22	77	49	154
Net income	71	244	157	487
Foreign Currency Translation Adjustments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss)	(78)	(3)	(78)	(3)	(26)	(21)	(12)	(31)
Other comprehensive income (loss) before reclassifications	(52)	9	(57)	28
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Other comprehensive income (loss), net of tax	(52)	9	(57)	28
Other
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss)	(20)	(24)	(20)	(24)	(20)	(20)	(24)	(23)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	(1)
Other comprehensive income (loss), net of tax	0	0	0	(1)
Other | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations before income taxes	0	0	0	1
Net income	0	0	0	1
Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss)	(6,916)	1,792	(6,916)	1,792	$ (4,093)	$ 374	$ 1,783	$ 3,494
Other comprehensive income (loss) before reclassifications	(2,757)	253	(7,138)	(1,211)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(66)	(244)	(152)	(491)
Other comprehensive income (loss), net of tax	$ (2,823)	$ 9	$ (7,290)	$ (1,702)