Net Unrealized Gains and Losses on Available-for-Sale Investment Securities Reflected as Separate Component of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Components of Net Unrealized Investment Gains Losses Included in Accumulated Other Comprehensive Income Loss [Line Items]
Net unrealized gains (losses) on fixed maturity securities without an allowance for credit losses	$ (2,577)	$ (4,251)	$ 7,869
Net unrealized gains (losses) on fixed maturity securities with an allowance for credit losses	0	0	0
Adjustments to policyholder contract balances	52	68	(131)
Income taxes, net	352	705	(1,646)
Net unrealized investment gains (losses)	(2,173)	(3,478)	6,092
Less: net unrealized investment gains (losses) attributable to noncontrolling interests	(43)	(71)	15
Net unrealized investment gains (losses)	$ (2,130)	$ (3,407)	$ 6,077	$ 7,820