DERIVATIVES - Schedule of Fair Value Hedges (Details) - Hedge of interest rate risk - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest expense - long-term borrowed funds
Derivative Instruments, Gain (Loss) [Line Items]
Derivative	$ (72)	$ 65	$ 107
Hedged Item	71	(63)	(107)
Interest and fees on loans and leases
Derivative Instruments, Gain (Loss) [Line Items]
Derivative	0	17	(17)
Hedged Item	0	(17)	17
Interest income - investment securities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative	68	(104)	8
Hedged Item	$ (68)	$ 104	$ (8)

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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