Reinsurance - Reinsurance Recoverables (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2019	Dec. 31, 2018
Ceded Credit Risk [Line Items]
Current reinsurance recoverables	$ 289	$ 297
Reinsurance recoverables	5,563	5,804
Ongoing Operations [Member]
Ceded Credit Risk [Line Items]
Maximum reinsurance recoverable from a single reinsurer	66
Ongoing Operations [Member] \| Maximum [Member]
Ceded Credit Risk [Line Items]
Minimum reinsurance recoverable from a single reinsurer	$ 1
Ongoing Operations [Member] \| Minimum [Member] \| Standard & Poor's Investment Grade [Member] \| Reinsurance Recoverable [Member]
Ceded Credit Risk [Line Items]
Concentration Risk, Percentage	70.00%
Acquisition, disposition or runoff activities [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 5,065	5,340
The Lincoln National Life Insurance Company And Lincoln Life And Annuity Of New York [Member] \| Individual Life Insurance And Annuity (sold in 1998) [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	3,194	3,312
Berkshire [Member] \| Guaranteed Minimum Death Benefits [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 817	893
Berkshire [Member] \| Guaranteed Minimum Death Benefits [Member] \| Ceded Credit Risk Secured [Member] \| Reinsurance Recoverable [Member]
Ceded Credit Risk [Line Items]
Concentration Risk, Percentage	100.00%
Prudential Retirement Insurance And Annuity Company [Member] \| Retirement Benefits Business (sold in 2004) [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 729	787
Prudential Retirement Insurance And Annuity Company [Member] \| Retirement Benefits Business (sold in 2004) [Member] \| Ceded Credit Risk Secured [Member] \| Reinsurance Recoverable [Member]
Ceded Credit Risk [Line Items]
Concentration Risk, Percentage	100.00%
Great American Life Insurance Company [Member] \| Supplemental Benefits Business (2012 acquistion) [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 244	261
Great American Life Insurance Company [Member] \| Supplemental Benefits Business (2012 acquistion) [Member] \| Ceded Credit Risk Secured [Member] \| Reinsurance Recoverable [Member]
Ceded Credit Risk [Line Items]
Concentration Risk, Percentage	100.00%
Other Retrocessionaires [Member] \| Ongoing Operations [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 498	464
Other Retrocessionaires [Member] \| Integrated Medical, International Markets, Group Disability, COLI [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	498	464
Other Retrocessionaires [Member] \| Other run-off reinsurance [Member]
Ceded Credit Risk [Line Items]
Reinsurance recoverables	$ 81	$ 87
Other Retrocessionaires [Member] \| Other run-off reinsurance [Member] \| Ceded Credit Risk Secured [Member] \| Reinsurance Recoverable [Member]
Ceded Credit Risk [Line Items]
Concentration Risk, Percentage	100.00%

Out of a specified group or category, the maximum reinsurance recoverable from a single reinsurer.

No definition available.

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- Definition

Out of a specified group or category, the minimum reinsurance recoverable balance from a single reinsurer.

+ References

No definition available.

+ Details

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- Definition

Amount, after valuation allowance, recoverable within one year under reinsurance contracts including premium paid under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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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

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
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-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
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-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

+ Details

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- Definition

Amount, after valuation allowance, recoverable under reinsurance contracts including premium paid under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.(a),6)
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 310
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=99404803&loc=d3e21409-158489

+ Details

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