INVESTMENT SECURITIES AND OTHER SECURITIES - Realized Securities Gains (Losses) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
Investments, Debt and Equity Securities [Abstract] | |||
Available-for-sale Securities, Gross Realized Gains | $ 7 | $ 10 | $ 23 |
Available-for-sale Securities, Gross Realized Losses | (28) | (10) | (21) |
Debt and Equity Securities, Gain (Loss) | (21) | 0 | 2 |
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities | 0 | (4) | (2) |
Available-for-sale Securities, Gross Realized Gain (Loss) | $ (21) | $ (4) | $ 0 |