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Derivative Instruments and Hedging Activities - Hedged Items in Fair Value Hedging Relationship (Detail) - USD ($) $ in Millions | Mar. 31, 2020 | Dec. 31, 2019
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Hedged Items In Fair Value Hedging Relationship [Line Items] |  |
Amortized cost of closed prepayment assets | $ 1,900 | $ 5,900
Amortized cost of closed prepayable assets, designated hedged items | 1,300 | 3,100
Hedged assets cumulative basis adjustment | 95 | 75
Available-for-sale securities |  |
Hedged Items In Fair Value Hedging Relationship [Line Items] |  |
Carrying Amount of Assets | 6,722 | 10,825
Hedged Assets, Fair Value Hedge, Cumulative Increase (Decrease) | 638 | 300
Hedged Assets, Discontinued Fair Value Hedge, Cumulative Increase (Decrease) | 118 | 52
Interest-bearing deposits |  |
Hedged Items In Fair Value Hedging Relationship [Line Items] |  |
Carrying Amount Of Liabilities | (14,399) | (14,310)
Hedged Liabilities, Fair Value Hedge, Cumulative Increase (Decrease) | (296) | (12)
Hedged Liabilities, Discontinued Fair Value Hedge, Cumulative Increase (Decrease) | 0 | 0
Securitized debt obligations |  |
Hedged Items In Fair Value Hedging Relationship [Line Items] |  |
Carrying Amount Of Liabilities | (10,010) | (9,403)
Hedged Liabilities, Fair Value Hedge, Cumulative Increase (Decrease) | (248) | 44
Hedged Liabilities, Discontinued Fair Value Hedge, Cumulative Increase (Decrease) | 51 | 64
Senior and subordinated notes |  |
Hedged Items In Fair Value Hedging Relationship [Line Items] |  |
Carrying Amount Of Liabilities | (29,353) | (27,777)
Hedged Liabilities, Fair Value Hedge, Cumulative Increase (Decrease) | (1,549) | (458)
Hedged Liabilities, Discontinued Fair Value Hedge, Cumulative Increase (Decrease) | $ 304 | $ 324

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- Definition [Line Items] for Table shows the carrying amount and associated cumulative basis adjustment related to the application of hedge accounting that is included in the carrying amount of hedged assets and liabilities in fair value hedging relationships. + References No definition available. + Details
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