Investments - Narrative (Details) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) security	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Schedule of Investments [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				77.00%
Percentage (based on fair value) of available for sale fixed maturities that are in an unrealized loss position and rated investment grade				84.00%
Net investment income	$ 572		$ 588	$ 1,584	$ 1,710
Fixed maturities
Schedule of Investments [Line Items]
Gross unrealized losses on fixed maturities	254			$ 254		$ 88
Number of available for sale securities in an unrealized loss position | security				759
Residential MBS
Schedule of Investments [Line Items]
Gross unrealized losses on fixed maturities	6			$ 6		$ 5
Number of securities purchased with credit deterioration | security				2
Aggregate par value of securities purchased with credit deterioration, at time of purchase				$ 8
Aggregate purchase price of securities purchased with credit deterioration, at time of purchase				6
Initial allowance for purchased securities with credit deterioration				1
Initial discount for purchased securities with credit deterioration				1
Neon Capital Limited
Schedule of Investments [Line Items]
Net investment income	$ 1			$ (5)
Accounting Standards Update 2016-01 | Equity securities | Neon Capital Limited
Schedule of Investments [Line Items]
Net investment income		$ (7)