Derivative Financial Instruments - Fair Value of Derivative Instruments (Details) $ in Millions	Sep. 30, 2020 USD ($)
Derivative [Line Items]
Total asset derivatives	$ 404
Total liability derivatives	3,210
Reinsurance related embedded derivatives, included in accounts payable and accrued liabilities
Derivative [Line Items]
Total liability derivatives	49
Call options
Derivative [Line Items]
Total asset derivatives	381
Other derivatives and embedded derivatives | Investment in unconsolidated affiliates
Derivative [Line Items]
Total asset derivatives	23
FIA embedded derivative | Contractholder funds
Derivative [Line Items]
Total liability derivatives	$ 3,161