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Investment Securities - Narrative (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Marketable Securities [Abstract] |  |  |
Gain on sale of debt investment securities | $ 0 | $ 0 | $ 0
Loss on sale of debt investment securities | 0 | 4,000,000 | 0
Proceeds from sales |  | 629,000,000 | $ 192,000,000
Available-for-sale, accrued interest, after allowance for credit loss | 23,000,000 | 22,000,000 |
Held-to-maturity, accrued interest, after allowance for credit loss | 1,000,000 |  |
Allowance for credit losses for HTM securities | 0 | 0 |
Carrying amount of equity method investments without readily determinable fair value | 70,000,000 | 57,000,000 |
Unrealized gain (loss) for equity investments with readily determinable fair value | $ 3,000,000 | $ 7,000,000 |

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