Loans and Card Member Receivables (Details 4) account in Thousands, $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021 USD ($) account	Jun. 30, 2020 USD ($) account	Jun. 30, 2021 USD ($) account	Jun. 30, 2020 USD ($) account
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| account	28	143	74	170
Account Balances	$ 257	$ 2,001
Outstanding Balances			$ 669	$ 2,270
Card Member Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| account	23	116	61	140
Account Balances	$ 172	$ 1,103
Average Interest Rate Reduction (as a percentage)	13.00%	14.00%	13.00%	14.00%
Outstanding Balances			$ 459	$ 1,298
Card Member Receivables
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| account	4	22	11	25
Account Balances	$ 83	$ 744
Average Payment Term Extension (in months)	18 months	18 months	18 months	19 months
Outstanding Balances			$ 200	$ 818
Other Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| account	1	5	2	5
Account Balances	$ 2	$ 154
Average Interest Rate Reduction (as a percentage)	3.00%	4.00%	3.00%	400.00%
Average Payment Term Extension (in months)	18 months	15 months	15 months	15 months
Outstanding Balances			$ 10	$ 154

The average basis point reduction in interest rate by class of Financial Instrument

No definition available.

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- Definition

The average period for payment term extension for cardmember receivables modified in a TDR.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524

+ Details

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- Definition

Amount, after troubled debt restructuring, of modified financing receivable.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount, before troubled debt restructuring, of financing receivable to be modified.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
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- Details

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- Details

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- Details

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