Investment Securities - Gains and Losses Recognized in Income from Securities (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Available-for-sale debt and other securities:
Realized gains	$ 34	$ 16	$ 34
Realized losses	(30)	(13)	(19)
Impairment losses	(5)	(1)	(19)
Net realized (losses) gains on available-for-sale debt and other securities	(1)	2	(4)
Trading debt securities:
Net realized losses	0	(2)	(2)
Net unrealized gains (losses)	3	11	(3)
Net trading debt securities gains (losses)	3	9	(5)
Equity securities:
Net realized gains	5	1	7
Net unrealized gains (losses)	11	(96)	(7)
Net equity securities gains (losses)	16	(95)	0
Total (losses) gains recognized in income from available-for-sale debt and other securities, trading debt securities and equity securities	(18)	84	9
Commercial Banking Revenue and Wealth and Asset Management Revenue
Equity securities:
Total (losses) gains recognized in income from available-for-sale debt and other securities, trading debt securities and equity securities	$ (13)	$ 0	$ 7

Total available for sale and trading securities gains losses.

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Amount of unrealized and realized gain (loss) 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 of realized gain 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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