Account Balances of Variable Annuity Contract with Death or Living Benefit Guarantees Invested in Separate Account Investment Options (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Separate account investment	$ 2,807	$ 3,796
Balanced funds
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Separate account investment	1,686	2,397
Equity funds
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Separate account investment	721	913
Bond funds
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Separate account investment	214	297
Money market funds
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Separate account investment	$ 186	$ 189