Activity Associated with Derivative Instruments (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($) Policies
Derivative [Line Items]
Notional amount, beginning balance	$ 11,025
Additions	2,341
Maturities/ terminations	(1,777)
Notional amount, ending balance	11,589
Designated As Hedging Instrument
Derivative [Line Items]
Notional amount, beginning balance	8,686
Additions	669
Maturities/ terminations	(55)
Notional amount, ending balance	9,300
Designated As Hedging Instrument | Cash Flow Hedges
Derivative [Line Items]
Notional amount, beginning balance	8,686
Additions	669
Maturities/ terminations	(55)
Notional amount, ending balance	9,300
Designated As Hedging Instrument | Cash Flow Hedges | Interest rate swaps
Derivative [Line Items]
Notional amount, beginning balance	8,542
Additions	669
Maturities/ terminations	(42)
Notional amount, ending balance	9,169
Designated As Hedging Instrument | Cash Flow Hedges | Foreign currency swaps
Derivative [Line Items]
Notional amount, beginning balance	144
Additions	0
Maturities/ terminations	(13)
Notional amount, ending balance	131
Derivatives not designated as hedges
Derivative [Line Items]
Notional amount, beginning balance	2,339
Additions	1,672
Maturities/ terminations	(1,722)
Notional amount, ending balance	2,289
Derivatives not designated as hedges | Equity index options
Derivative [Line Items]
Notional amount, beginning balance	936
Additions	194
Maturities/ terminations	(277)
Notional amount, ending balance	853
Derivatives not designated as hedges | Financial futures
Derivative [Line Items]
Notional amount, beginning balance	1,403
Additions	1,478
Maturities/ terminations	(1,445)
Notional amount, ending balance	$ 1,436
Derivatives not designated as hedges | Fixed index annuity embedded derivatives
Derivative [Line Items]
Notional amount, beginning balance | Policies	7,315
Additions | Policies	0
Maturities/ terminations | Policies	(504)
Notional amount, ending balance | Policies	6,811
Derivatives not designated as hedges | Indexed universal life embedded derivatives
Derivative [Line Items]
Notional amount, beginning balance | Policies	771
Additions | Policies	0
Maturities/ terminations | Policies	(6)
Notional amount, ending balance | Policies	765