Investment Securities - Components of Available-for-Sale Investment Securities Portfolio (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 29,502	$ 27,370
Unrealized Gains	0	164
Unrealized Losses	(2,791)	(313)
Carrying value	26,711	27,221
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	18,041	15,799
Unrealized Gains	0	121
Unrealized Losses	(1,196)	(70)
Carrying value	16,845	15,850
U.S. agency debentures
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	120	200
Unrealized Gains	0	0
Unrealized Losses	(20)	(4)
Carrying value	100	196
Foreign government debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,062	61
Unrealized Gains	0	0
Unrealized Losses	(149)	0
Carrying value	913	61
Agency-issued MBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,883	8,786
Unrealized Gains	0	13
Unrealized Losses	(1,200)	(210)
Carrying value	6,683	8,589
Agency-issued CMO—fixed rate
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	792	988
Unrealized Gains	0	3
Unrealized Losses	(78)	(9)
Carrying value	714	982
Agency-issued CMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,604	1,536
Unrealized Gains	0	27
Unrealized Losses	(148)	(20)
Carrying value	$ 1,456	$ 1,543

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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