v3.26.3
Investments - Schedule of Residential Mortgage-Backed Securities (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Summary of Investment Holdings [Line Items]    
Amortized Cost $ 63,389 $ 53,961
Allowance for Credit Loss 4 11
Gross Unrealized Gains 81 592
Gross Unrealized Losses 5,856 3,751
Fair Value 57,610 50,791
Non-agency RMBS    
Summary of Investment Holdings [Line Items]    
Amortized Cost 314 310
Allowance for Credit Loss 1 4
Gross Unrealized Gains 18 23
Gross Unrealized Losses 30 15
Fair Value 301 314
Non-agency RMBS | Prime    
Summary of Investment Holdings [Line Items]    
Amortized Cost 259 280
Allowance for Credit Loss 1 2
Gross Unrealized Gains 2 3
Gross Unrealized Losses 23 13
Fair Value 237 268
Non-agency RMBS | Alt-A    
Summary of Investment Holdings [Line Items]    
Amortized Cost 19 23
Allowance for Credit Loss 0 2
Gross Unrealized Gains 12 16
Gross Unrealized Losses 7 2
Fair Value 24 35
Non-agency RMBS | Subprime    
Summary of Investment Holdings [Line Items]    
Amortized Cost 36 7
Allowance for Credit Loss 0 0
Gross Unrealized Gains 4 4
Gross Unrealized Losses 0 0
Fair Value $ 40 $ 11