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Investments (Narrative) (Detail) $ in Millions	12 Months Ended
Investments (Narrative) (Detail) $ in Millions	Dec. 31, 2021	Dec. 31, 2020 USD ($) partnerships	Dec. 31, 2019 USD ($)
Investment [Line Items]
Document Period End Date		Dec. 31, 2020
Limited partnerships number \| partnerships		130
Restricted assets in fixed maturities and short-term investments		$ 19,600	$ 21,000
Restricted assets in cash		89	$ 109
Debt Securities, Available-for-sale, Purchased with Credit Deterioration, Amount at Purchase Price		108
Debt Securities, Available-for-sale, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date		5
Debt Securities, Available-for-sale, Purchased with Credit Deterioration, Amount at Par Value		$ 144
Huatai Group [Member]
Investment [Line Items]
Ownership Percentage		47.10%
CHINA \| Huatai Group [Member]
Investment [Line Items]
Ownership Percentage		47.00%	31.00%
Equity method investment, additional 15.3 ownership percentage obtained			15.30%
Equity method investment, additional 7.1 percentage obtained		7.10%
CHINA \| Huatai Life Insurance Co. [Member]
Investment [Line Items]
Ownership Percentage		20.00%	20.00%
Subsequent Event [Member] \| CHINA \| Huatai Group [Member]
Investment [Line Items]
Equity method investment, additional 7.1 percentage obtained	7.10%
Indirect Ownership [Member] \| CHINA \| Huatai Life Insurance Co. [Member]
Investment [Line Items]
Ownership Percentage		37.50%
Direct Ownership [Member] \| CHINA \| Huatai Life Insurance Co. [Member]
Investment [Line Items]
Ownership Percentage		20.00%