DERIVATIVES - Schedule of Fair Value Hedges (Details) - Interest rate swap - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest expense - borrowed funds
Derivative Instruments, Gain (Loss) [Line Items]
Derivative	$ (16)	$ 18	$ 82	$ 122
Hedged Item	17	(18)	(78)	(121)
Interest and fees on loans and leases
Derivative Instruments, Gain (Loss) [Line Items]
Derivative	0	(10)	17	(26)
Hedged Item	0	10	(17)	26
Interest income - investment securities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative	7	(13)	(114)	(13)
Hedged Item	$ (7)	$ 13	$ 114	$ 13

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=121577467&loc=d3e76258-113986

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- Definition

Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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