Additional Information - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Allowance for reinsurance recoverables [Line Items]
Commitments to fund limited partnerships	$ 993
Retirement and employee savings plan expense	$ 41	$ 39	$ 37
Great American Life Insurance Company
Allowance for reinsurance recoverables [Line Items]
Percent of commitments to fund limited partnerships related Great American Life Insurance Company	0.50