LOANS - Schedule of Purchased Credit Deteriorated Assets (Details) $ in Millions	3 Months Ended
Sep. 30, 2020 USD ($)
Credit cards
Financing Receivable, Purchased with Credit Deterioration, Amount at Purchase Price [Abstract]
Purchase price	$ 0
Allowance for credit losses at acquisition date	0
Discount or premium attributable to non-credit factors	0
Par value (amortized cost basis)	0
Mortgages
Financing Receivable, Purchased with Credit Deterioration, Amount at Purchase Price [Abstract]
Purchase price	25
Allowance for credit losses at acquisition date	0
Discount or premium attributable to non-credit factors	0
Par value (amortized cost basis)	25
Installment and other
Financing Receivable, Purchased with Credit Deterioration, Amount at Purchase Price [Abstract]
Purchase price	0
Allowance for credit losses at acquisition date	0
Discount or premium attributable to non-credit factors	0
Par value (amortized cost basis)	$ 0

Amount of allowance for credit loss at acquisition date of financing receivable purchased with credit deterioration.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 19
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919265-210447

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount at par value of financing receivable purchased with credit deterioration.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 19
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919265-210447

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount at purchase price of financing receivable purchased with credit deterioration.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 19
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919265-210447

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of discount (premium) attributable to other factors on financing receivable purchased with credit deterioration.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 19
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919265-210447

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CreditCardReceivablesMember
Namespace Prefix:
Data Type:	na
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- Details

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- Details

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