Reinsurance (Reinsurance Introduction - Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Effects of Reinsurance [Line Items]
Reinsurance Recoverables, Ceded	$ 13,800	$ 12,700
Mortality Risk [Member]
Effects of Reinsurance [Line Items]
Reinsurance Retention Policy, Excess Retention, Percentage	90.00%
Reinsurance Retention Policy, Amount Retained	$ 2
Mortality Risk on Case by Case Basis [Member]
Effects of Reinsurance [Line Items]
Reinsurance Retention Policy, Excess Retention, Percentage	100.00%
Reinsurance Retention Policy, Amount Retained	$ 20
Participating Life Insurance Contract [Member]
Effects of Reinsurance [Line Items]
Reinsurance Retention Policy, Excess Retention, Percentage	90.00%
Quota Share Reinsurance for Certain Disability Business [Member]
Effects of Reinsurance [Line Items]
Reinsurance Retention Policy, Reinsured Risk, Percentage	100.00%
Ceded Credit Risk, Secured [Member] \| Accident and Health Insurance Product Line [Member]
Effects of Reinsurance [Line Items]
Reinsurance Recoverables, Ceded	$ 6,700

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

Stated amount that is the upper retention limit per entity policy.

+ References

No definition available.

+ Details

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- Definition

Percentage of risk reinsured in excess of stated retention per entity policy.

+ References

No definition available.

+ Details

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- Definition

Percentage of risk reinsured on insurance products per entity policy.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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