Derivatives (Fair Value Hedges) (Details) - Designated as Hedging Instrument [Member] - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Mortgage loans
Derivative Instruments, Gain (Loss) [Line Items]
Debt Instruments, Carrying Amount	$ 837	$ 1,127
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	20	2
Future policy benefits [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Debt Instruments, Carrying Amount	(5,668)	(4,475)
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	(1,521)	(908)
Fixed Maturities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedged Asset, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	(1)	(1)
Debt Instruments, Carrying Amount	422	404
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	$ (1)	$ (1)

Debt Instruments, Carrying Amount

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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 of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk, remaining after discontinued hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4EE
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL109999712-113959

+ Details

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Namespace Prefix:	us-gaap_
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- Definition

Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4EE
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL109999712-113959

+ Details

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