v3.26.1
Derivative Instruments - Notional and Fair Value Position (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Derivative [Line Items]    
Notional Amount $ 697,607 $ 668,079
Asset Derivatives    
Derivative assets, gross amount offset (38) (199)
Derivative assets 386 177
Liability Derivatives    
Derivatives liabilities at fair value (270) (152)
Table Footnote [Abstract]    
Cash collateral posted for derivative instruments 1,400 1,100
Cash collateral received for derivative instruments 16 27
Total risk management derivatives portfolio    
Derivative [Line Items]    
Notional Amount 459,140 477,083
Asset Derivatives    
Derivative assets, gross amount offset (38) (199)
Derivative assets 167 78
Liability Derivatives    
Netting adjustment 1,383 1,242
Derivatives liabilities at fair value (38) (14)
Total risk management derivatives portfolio | Designated as Hedging Instrument    
Derivative [Line Items]    
Notional Amount 63,056 47,198
Asset Derivatives    
Derivative assets, gross 0 0
Liability Derivatives    
Derivative liabilities, gross 0 0
Total risk management derivatives portfolio | Not Designated as Hedging Instrument    
Derivative [Line Items]    
Notional Amount 396,084 429,885
Asset Derivatives    
Derivative assets, gross 205 277
Liability Derivatives    
Derivative liabilities, gross (1,421) (1,256)
Pay-fixed | Designated as Hedging Instrument    
Derivative [Line Items]    
Notional Amount 44,955 38,759
Asset Derivatives    
Derivative assets, gross 0 0
Liability Derivatives    
Derivative liabilities, gross 0 0
Pay-fixed | Not Designated as Hedging Instrument    
Derivative [Line Items]    
Notional Amount 158,644 199,744
Asset Derivatives    
Derivative assets, gross 0 0
Liability Derivatives    
Derivative liabilities, gross 0 0
Receive-fixed | Designated as Hedging Instrument    
Derivative [Line Items]    
Notional Amount 18,101 8,439
Asset Derivatives    
Derivative assets, gross 0 0
Liability Derivatives    
Derivative liabilities, gross 0 0
Receive-fixed | Not Designated as Hedging Instrument    
Derivative [Line Items]    
Notional Amount 195,328 194,394
Asset Derivatives    
Derivative assets, gross 88 145
Liability Derivatives    
Derivative liabilities, gross (1,221) (1,082)
Basis | Not Designated as Hedging Instrument    
Derivative [Line Items]    
Notional Amount 250 250
Asset Derivatives    
Derivative assets, gross 35 28
Liability Derivatives    
Derivative liabilities, gross 0 0
Foreign currency | Not Designated as Hedging Instrument    
Derivative [Line Items]    
Notional Amount 329 334
Asset Derivatives    
Derivative assets, gross 0 0
Liability Derivatives    
Derivative liabilities, gross (63) (56)
Pay-fixed | Not Designated as Hedging Instrument    
Derivative [Line Items]    
Notional Amount 20,145 11,956
Asset Derivatives    
Derivative assets, gross 78 91
Liability Derivatives    
Derivative liabilities, gross (17) (4)
Receive-fixed | Not Designated as Hedging Instrument    
Derivative [Line Items]    
Notional Amount 10,351 11,661
Asset Derivatives    
Derivative assets, gross 4 13
Liability Derivatives    
Derivative liabilities, gross (120) (114)
Futures | Not Designated as Hedging Instrument    
Derivative [Line Items]    
Notional Amount 11,037 11,546
Asset Derivatives    
Derivative assets, gross 0 0
Liability Derivatives    
Derivative liabilities, gross 0 0
Mortgage commitment derivatives    
Derivative [Line Items]    
Notional Amount 208,427 162,995
Asset Derivatives    
Derivative assets, gross amount offset 0 0
Derivative assets 178 55
Liability Derivatives    
Netting adjustment 0 0
Derivatives liabilities at fair value (193) (131)
Mortgage commitments to purchase whole loans    
Derivative [Line Items]    
Notional Amount 4,790 4,005
Asset Derivatives    
Derivative assets 6 7
Liability Derivatives    
Derivatives liabilities at fair value (2) (1)
Forward contracts to purchase mortgage-related securities    
Derivative [Line Items]    
Notional Amount 70,038 47,122
Asset Derivatives    
Derivative assets 55 48
Liability Derivatives    
Derivatives liabilities at fair value (112) (13)
Forward contracts to sell mortgage-related securities    
Derivative [Line Items]    
Notional Amount 133,599 111,868
Asset Derivatives    
Derivative assets 117 0
Liability Derivatives    
Derivatives liabilities at fair value (79) (117)
Credit enhancement derivatives    
Derivative [Line Items]    
Notional Amount 26,033 27,269
Asset Derivatives    
Derivative assets 41 44
Liability Derivatives    
Derivatives liabilities at fair value (4) (3)
Other derivatives    
Derivative [Line Items]    
Notional Amount 4,007 732
Asset Derivatives    
Derivative assets 0 0
Liability Derivatives    
Derivatives liabilities at fair value $ (35) $ (4)