v3.21.2
Derivatives and Hedging Activities - Bifurcated Embedded Derivatives (Detail) - USD ($)
$ in Millions
Sep. 30, 2021
Dec. 31, 2020
Derivative [Line Items]    
Embedded Derivative, Fair Value of Embedded Derivative Asset $ 881 $ 1,450
Embedded Derivative, Fair Value of Embedded Derivative Liability (1,389) (1,220)
Embedded Derivative, Fair Value of Embedded Derivative, Net Liability (508) 230
Notional amount 42,070,294 38,600,406
Embedded Derivatives Classified In Debt [Member]    
Derivative [Line Items]    
Notional amount $ 11,765 $ 12,548