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Investment Securities - Schedule Of Investments Within The Available For Sale Portfolio That Had Unrealized Losses (Details) - USD ($) $ in Millions | Jun. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Schedule of Investments [Line Items] |  |
Less than 12 months | $ 3,272 | $ 1,400
12 months or longer | 0 | 0
Total fair value | 3,272 | 1,400
Unrealized Losses |  |
Less than 12 months | (48) | (6)
12 months or longer | 0 | 0
Total unrealized losses | (48) | (6)
U.S. treasuries |  |
Schedule of Investments [Line Items] |  |
Less than 12 months |  | 307
12 months or longer |  | 0
Total fair value |  | 307
Unrealized Losses |  |
Less than 12 months |  | 0
12 months or longer |  | 0
Total unrealized losses |  | 0
Government agency issued MBS |  |
Schedule of Investments [Line Items] |  |
Less than 12 months | 1,618 | 426
12 months or longer | 0 | 0
Total fair value | 1,618 | 426
Unrealized Losses |  |
Less than 12 months | (19) | (2)
12 months or longer | 0 | 0
Total unrealized losses | (19) | (2)
Government agency issued CMO |  |
Schedule of Investments [Line Items] |  |
Less than 12 months | 1,332 | 586
12 months or longer | 0 | 0
Total fair value | 1,332 | 586
Unrealized Losses |  |
Less than 12 months | (25) | (3)
12 months or longer | 0 | 0
Total unrealized losses | (25) | (3)
Other U.S. government agencies |  |
Schedule of Investments [Line Items] |  |
Less than 12 months | 281 | 80
12 months or longer | 0 | 0
Total fair value | 281 | 80
Unrealized Losses |  |
Less than 12 months | (4) | (1)
12 months or longer | 0 | 0
Total unrealized losses | (4) | (1)
States and municipalities |  |
Schedule of Investments [Line Items] |  |
Less than 12 months | 41 | 1
12 months or longer | 0 | 0
Total fair value | 41 | 1
Unrealized Losses |  |
Less than 12 months | 0 | 0
12 months or longer | 0 | 0
Total unrealized losses | $ 0 | $ 0

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