Reinsurance (Reinsurance Introduction - Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Effects of Reinsurance [Line Items]
Reinsurance Retention Policy, Reinsured Risk, Percentage	100.00%
Reinsurance Retention Policy, Excess Retention, Percentage	100.00%
Reinsurance Recoverables, Ceded	$ 18,700	$ 17,300
Maximum
Effects of Reinsurance [Line Items]
Reinsurance, Amount Retained, Per Life	$ 20
Participating whole life insurance
Effects of Reinsurance [Line Items]
Reinsurance Retention Policy, Reinsured Risk, Percentage	90.00%
Accident & health insurance
Effects of Reinsurance [Line Items]
Reinsurance Retention Policy, Reinsured Risk, Percentage	100.00%
Ceded Credit Risk, Secured [Member] \| Accident & health insurance
Effects of Reinsurance [Line Items]
Reinsurance Recoverables, Ceded	$ 5,800
Ceded Credit Risk, Unsecured [Member]
Effects of Reinsurance [Line Items]
Reinsurance Recoverables, Ceded	$ 6,000	$ 6,000

Amount of reinsurance recoverable balances in both asset and liability accounts that have been ceded.

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount per life of risk undertaken originally by insurer that is not ceded to reinsurer.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479838/944-20-50-3

+ Details

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- Definition

Percentage of risk ceded to reinsurer in excess of risk undertaken originally by insurer that is not ceded to reinsurer.

+ References

+ Details

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- Definition

Percentage of risk undertaken originally by insurer ceded to reinsurer.

+ References

+ Details

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- Details

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