Investment Securities - Gross Unrealized Losses (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Estimated Fair Value
Less than 12 months	$ 0	$ 0
12 months or more	188	1,154
Gross Unrealized Losses
Less than 12 months	0	0
12 months or more	(12)	(19)
State and municipal obligations
Estimated Fair Value
Less than 12 months	0	0
12 months or more	29	33
Gross Unrealized Losses
Less than 12 months	0	0
12 months or more	(7)	(6)
U.S. Government treasury obligations
Estimated Fair Value
Less than 12 months	0	0
12 months or more	150	1,114
Gross Unrealized Losses
Less than 12 months	0	0
12 months or more	(4)	(12)
Mortgage-backed securities
Estimated Fair Value
Less than 12 months	0	0
12 months or more	9	7
Gross Unrealized Losses
Less than 12 months	0	0
12 months or more	$ (1)	$ (1)

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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