Investments - Narrative (Details) $ in Millions	12 Months Ended
Dec. 31, 2019 USD ($) security	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Investment [Line Items]
Percentage (based on amount of unrealized loss) of available for sale fixed maturities that are in an unrealized loss position and rated investment grade	74.00%
Percentage (based on fair value) of available for sale fixed maturities that are in an unrealized loss position and rated investment grade	93.00%
Other than temporary impairment charges	$ 19	$ 19	$ 73
Average life of CLOs and Other ABS	4 years
Average life of MBS	4 years 6 months
Residential MBS
Investment [Line Items]
Non-credit related portion of other-than-temporary impairment charges taken for securities still owned	$ 118	140
Fixed maturities, Gross Unrealized, Losses	(5)	(9)
Other than temporary impairment charges	1	6	1
Collateralized loan obligations
Investment [Line Items]
Fixed maturities, Gross Unrealized, Losses	(37)	(73)
Other than temporary impairment charges	17
Corporate bond securities
Investment [Line Items]
Other than temporary impairment charges	11
Securities with non-credit other-than-temporary impairment charges
Investment [Line Items]
Gross Unrealized, Gains	114	119
Gross Unrealized, Losses	(1)	(4)
Fixed maturities
Investment [Line Items]
Fixed maturities, Gross Unrealized, Losses	$ (88)	(603)
Number of available for sale securities in an unrealized loss position \| security	649
Other than temporary impairment charges	$ 29	26	20
Available-for-sale Securities, Gross Realized Gains	35	22	43
Available-for-sale Securities, Gross Realized Losses	(19)	(14)	(20)
Fixed maturities excluding residential MBS
Investment [Line Items]
Other than temporary impairment charges		20	19
Other investments
Investment [Line Items]
Other than temporary impairment charges			4
Equity securities
Investment [Line Items]
Other than temporary impairment charges	$ 0	$ 0	64
Available-for-sale Securities, Gross Realized Gains			87
Available-for-sale Securities, Gross Realized Losses			(17)
Equity securities \| Available-for-sale securities
Investment [Line Items]
Other than temporary impairment charges			$ 64

Collateralized loan obligations and Other asset-backed securities average useful life.

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Mortgage backed securities average useful life.

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Non-credit related portion of other-than-temporary impairment charges taken for securities still owned.

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Number of available-for-sale securities in an unrealized loss position.

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Percentage (based on fair value) of available for sale fixed maturities that are in an unrealized loss position and rated investment grade.

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Percentage based on unrealized loss of available for sale fixed maturities that are in an unrealized loss position and rated investment grade.

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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