Derivative Financial Instruments - Schedule of Change in Fair Value of Derivative Instruments (Details) - USD ($) $ in Millions	3 Months Ended		4 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019
Derivative [Line Items]
Change in fair value of reinsurance related embedded derivatives	$ (14)	$ 0		$ (35)	$ 0
Net investment (losses) gains
Derivative [Line Items]
Change in fair value of reinsurance related embedded derivatives	34		$ 28
Call options | Net investment (losses) gains
Derivative [Line Items]
Change in fair value of reinsurance related embedded derivatives	43		55
Futures contracts | Net investment (losses) gains
Derivative [Line Items]
Change in fair value of reinsurance related embedded derivatives	7		9
Foreign currency forward | Net investment (losses) gains
Derivative [Line Items]
Change in fair value of reinsurance related embedded derivatives	(4)		(4)
Other derivatives and embedded derivatives | Net investment (losses) gains
Derivative [Line Items]
Change in fair value of reinsurance related embedded derivatives	2		3
Reinsurance related embedded derivatives, included in accounts payable and accrued liabilities | Net investment (losses) gains
Derivative [Line Items]
Change in fair value of reinsurance related embedded derivatives	(14)		(35)
FIA embedded derivative
Derivative [Line Items]
Change in fair value of reinsurance related embedded derivatives	$ 209		$ 309