SECURITIES - Income Recognized from Investment Securities (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gain (Loss) on Sale of Investments [Abstract]
Gains on sale of debt securities	$ 11	$ 18	$ 41
Losses on sale of debt securities	0	(2)	(12)
Debt securities gains, net	11	16	29
Equity securities gains	$ 1	$ 3	$ 3

The net realized gain (loss) on investments sold during the period, not including gains (losses) on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, which, for cash flow reporting, is a component of proceeds from investing activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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- References

No definition available.

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- Definition

Amount of gain (loss) included in earnings for investments classified as other.

+ References

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- Definition

The difference between the carrying value and the sale price of an investment. A gain would be recognized when the sale price of the investment is greater than the carrying value of the investment. This element refers to the Gain included in earnings and not to the cash proceeds of the sale.

+ References

No definition available.

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- Definition

The difference between the carrying value and the sale price of an investment. A loss would be recognized when the sale price of the investment is less than the carrying value of the investment. This element refers to the Loss included in earnings and not to the cash proceeds of the sale.

+ References

No definition available.

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