Investments (Credit Losses Recognized in Earnings on Fixed Maturity Securities Held by the Company) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance, beginning of period	$ 0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Change in Status	41
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	(21)
Balance, end of period	20
Commercial Mortgage Backed Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance, beginning of period	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Change in Status	3
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	0
Balance, end of period	3
Foreign Government Debt [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance, beginning of period	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Change in Status	2
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	(2)
Balance, end of period	0
Corporate Debt Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance, beginning of period	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Change in Status	36
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	(19)
Balance, end of period	$ 17