Derivatives - Designated Fair Value Hedged Assets (Liabilities) (Details) - USD ($) $ in Millions |
Dec. 31, 2019 |
Dec. 31, 2018 |
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| Derivative [Line Items] | ||
| Hedged liability, long-term debt, carrying value | $ (162,389) | $ (138,682) |
| Hedged liability, long-term debt, cumulative fair value adjustments | (8,685) | (2,117) |
| Hedged asset, available-for-sale debt securities, carrying value | 1,654 | 981 |
| Hedged asset, available-for-sale debt securities, cumulative fair value adjustments | 64 | (29) |
| Interest rate risk on long-term debt | ||
| Derivative [Line Items] | ||
| Increase (decrease) in liability | (1,300) | (1,600) |
| Interest rate risk on AFS securities | ||
| Derivative [Line Items] | ||
| Available-for-sale securities from discontinued hedging relationships cumulative increase (decrease) | $ 8 | $ (29) |
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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. No definition available.
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- Definition Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk, remaining after discontinued hedge. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of asset hedged in fair value hedging relationship. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk, remaining after discontinued hedge. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of liability hedged in fair value hedging relationship. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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