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Derivative Instruments and Hedging Activities (Interest and Amortization on Derivative Instruments) (Details) - Designated as hedging instrument - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2020 | Jun. 30, 2019 | Jun. 30, 2020 | Jun. 30, 2019
Interest and fees on finance receivables and loans |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Total Interest And Amortization Income (Expense) Hedging Relationship | $ (51) | $ 2 | $ (73) | $ 4
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net |  |  | 1 | 0
Interest and dividends on investment securities and other earning assets |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Total Interest And Amortization Income (Expense) Hedging Relationship | (4) | (1) | (5) | (1)
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net |  |  | 0 | 0
Interest on long-term debt |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Total Interest And Amortization Income (Expense) Hedging Relationship | (4) | 1 | (4) | 1
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net |  |  | 0 | 1
Unsecured debt | Interest and fees on finance receivables and loans |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on amortization of deferred basis adjustments | 0 | 0 | 0 | 0
Unsecured debt | Interest and dividends on investment securities and other earning assets |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on amortization of deferred basis adjustments | 0 | 0 | 0 | 0
Unsecured debt | Interest on long-term debt |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on amortization of deferred basis adjustments | 2 | 6 | 8 | 12
Federal Home Loan Bank certificates and obligations | Interest and fees on finance receivables and loans |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on amortization of deferred basis adjustments | 0 | 0 | 0 | 0
Federal Home Loan Bank certificates and obligations | Interest and dividends on investment securities and other earning assets |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on amortization of deferred basis adjustments | 0 | 0 | 0 | 0
Federal Home Loan Bank certificates and obligations | Interest on long-term debt |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on amortization of deferred basis adjustments | (6) | (5) | (12) | (11)
Available-for-sale securities | Interest and fees on finance receivables and loans |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on amortization of deferred basis adjustments | 0 | 0 | 0 | 0
Gain (loss) on interest for qualifying hedge | 0 | 0 | 0 | 0
Available-for-sale securities | Interest and dividends on investment securities and other earning assets |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on amortization of deferred basis adjustments | (2) | (1) | (3) | (1)
Gain (loss) on interest for qualifying hedge | (2) | 0 | (2) | 0
Available-for-sale securities | Interest on long-term debt |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on amortization of deferred basis adjustments | 0 | 0 | 0 | 0
Gain (loss) on interest for qualifying hedge | 0 | 0 | 0 | 0
Fixed-rate automotive loans | Interest and fees on finance receivables and loans |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on amortization of deferred basis adjustments | (13) | (9) | (26) | (13)
Gain (loss) on interest for qualifying hedge | (38) | 11 | (47) | 17
Fixed-rate automotive loans | Interest and dividends on investment securities and other earning assets |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on amortization of deferred basis adjustments | 0 | 0 | 0 | 0
Gain (loss) on interest for qualifying hedge | 0 | 0 | 0 | 0
Fixed-rate automotive loans | Interest on long-term debt |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on amortization of deferred basis adjustments | 0 | 0 | 0 | 0
Gain (loss) on interest for qualifying hedge | $ 0 | $ 0 | 0 | 0
Variable-rate commercial loans | Interest and fees on finance receivables and loans |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on interest for qualifying hedge |  |  | 1 | 0
Variable-rate commercial loans | Interest and dividends on investment securities and other earning assets |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on interest for qualifying hedge |  |  | 0 | 0
Variable-rate commercial loans | Interest on long-term debt |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on interest for qualifying hedge |  |  | $ 0 | $ 0

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- Definition Total amount of interest and amortization of basis adjustment income (expense) on hedging relationships. + References No definition available. + Details
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- Definition The net gain (loss) recognized in earnings during the reporting period representing the amount of the cash flow hedges' ineffectiveness. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 + Details
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