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Derivatives Volume of Activity (Details) | 12 Months Ended
--- | ---
Dec. 31, 2019 USD ($)
Not Designated as Hedging Instrument, Economic Hedge [Member] | Interest rate swaps |
Derivative [Line Items] |
Beginning of Period, Notional Amount | $ 4,515,000,000
Notional Amount of Derivative Instruments Added | (6,560,000,000)
Notional Amount of Derivative Instruments Maturing, Settled, Terminated, or Paired-Off | (6,850,000,000)
End of Period, Notional Amount | 4,225,000,000
Not Designated as Hedging Instrument, Economic Hedge [Member] | Interest rate swaption |
Derivative [Line Items] |
Beginning of Period, Notional Amount | 0
Notional Amount of Derivative Instruments Added | (1,500,000,000)
Notional Amount of Derivative Instruments Maturing, Settled, Terminated, or Paired-Off | (750,000,000)
End of Period, Notional Amount | 750,000,000
Not Designated as Hedging Instrument, Economic Hedge [Member] | Eurodollar futures |
Derivative [Line Items] |
Beginning of Period, Notional Amount | 0
Notional Amount of Derivative Instruments Added | (9,000,000,000)
Notional Amount of Derivative Instruments Maturing, Settled, Terminated, or Paired-Off | (9,000,000,000)
End of Period, Notional Amount | 0
Not Designated as Hedging Instrument, Economic Hedge [Member] | U.S. Treasury futures |
Derivative [Line Items] |
Beginning of Period, Notional Amount | 50,000,000
Notional Amount of Derivative Instruments Added | 0
Notional Amount of Derivative Instruments Maturing, Settled, Terminated, or Paired-Off | (50,000,000)
End of Period, Notional Amount | 0
Not Designated as Hedging Instrument, Economic Hedge [Member] | Options on U.S. Treasury futures |
Derivative [Line Items] |
Beginning of Period, Notional Amount | 0
Notional Amount of Derivative Instruments Added | (1,350,000,000)
Notional Amount of Derivative Instruments Maturing, Settled, Terminated, or Paired-Off | 0
End of Period, Notional Amount | 1,350,000,000
Not Designated as Hedging Instrument, Economic Hedge [Member] | TBA securities | Short position |
Derivative [Line Items] |
Beginning of Period, Notional Amount | 0
Notional Amount of Derivative Instruments Added | (1,800,000,000)
Notional Amount of Derivative Instruments Maturing, Settled, Terminated, or Paired-Off | (2,300,000,000)
End of Period, Notional Amount | 500,000,000
Not Designated as Hedging Instrument, Trading | TBA securities | Long position |
Derivative [Line Items] |
Beginning of Period, Notional Amount | 860,000,000
Notional Amount of Derivative Instruments Added | (7,615,000,000)
Notional Amount of Derivative Instruments Maturing, Settled, Terminated, or Paired-Off | (8,040,000,000)
End of Period, Notional Amount | $ 435,000,000

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