SECURITIES - Schedule of Securities Pledged (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Pledged against repurchase agreements, Amortized Cost	$ 265	$ 344
Pledged against FHLB borrowed funds, Amortized Cost	638	745
Pledged against derivatives, to qualify for fiduciary powers, and to secure public and other deposits as required by law, Amortized Cost	3,670	3,592
Pledged against repurchase agreements, Fair Value	266	338
Pledged against FHLB borrowed funds, Fair Value	662	752
Pledged against derivatives, to qualify for fiduciary powers, and to secure public and other deposits as required by law, Fair Value	$ 3,672	$ 3,460

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- Definition

The fair value, as of the date of each statement of financial position presented, of securities which are owned but transferred to serve as collateral for the payment of the FHLB debt obligations, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66007379&loc=d3e113888-111728

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- Definition

The fair value, as of the date of each statement of financial position presented, of securities that are restricted as collateral for the payment of other debt obligations, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.

+ References

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- Definition

The fair value, as of the date of each statement of financial position presented, of securities which are owned but transferred to serve as collateral for the payment of repurchase agreements, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.

+ References

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- Definition

The carrying amount as of the date of the latest financial statement presented of securities which are owned but transferred to serve as collateral for FHLB debt obligations, and for which the transferee does not have the right by contract or custom to sell or re-pledge them to an unrelated party.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729

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- Definition

The carrying amount as of the date of the latest financial statement presented of securities which are owned but transferred to serve as collateral for debt facilities other than FHLB loans, repurchase agreements and letter of credit arrangements, and for which the transferee does not have the right by contract or custom to sell or re-pledge them to an unrelated party.

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- Definition

The carrying amount as of the date of the latest financial statement presented of securities which are owned but transferred to serve as collateral for repurchase agreements, and for which the transferee does not have the right by contract or custom to sell or re-pledge them to an unrelated party.

+ References

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