v3.20.4
Derivatives and Hedging Activities - Bifurcated Embedded Derivatives (Detail) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Derivative [Line Items]    
Embedded Derivative, Fair Value of Embedded Derivative Asset $ 1,450 $ 1,148
Embedded Derivative, Fair Value of Embedded Derivative Liability (1,220) (1,717)
Embedded Derivative, Fair Value of Embedded Derivative, Net Liability 230 (569)
Notional amount 38,600,406 39,750,315
Embedded Derivatives Classified In Debt [Member]    
Derivative [Line Items]    
Notional amount $ 12,548 $ 11,003