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Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Billions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items] |  |
Customer Reward Program | $ 5.4 | $ 4.7
Loan origination fees and direct loan origination costs amortization period | 12 months |
Minimum |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |
Partnership Agreement Initial Term | 2 years |
Maximum |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |
Partnership Agreement Initial Term | 10 years |
Credit Card |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |
Loan origination fees and direct loan origination costs amortization period | 12 months |
Amortization term of annual membership fees | 12 months |

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- Definition Amortization term of credit card annual membership fees + References No definition available. + Details
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Period Type: | duration

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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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- Details
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- Details
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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |