Investments (Impaired Mortgage Loans) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Financing Receivable Impaired [Line Items]
Unpaid Principal Balance		$ 36		$ 36		$ 37
Recorded Investment		36		36		37
Related Allowance		0		0		0
Carrying Value		36		36		37
Average Investment	[1]	36	$ 17	36	$ 17
Interest Income		1	0	1	0
Impaired mortgage loans with valuation allowance recorded
Financing Receivable Impaired [Line Items]
Unpaid Principal Balance		0		0		0
Recorded Investment		0		0		0
Related Allowance		0		0		0
Carrying Value		0		0		0
Impaired mortgage loans with no valuation allowance recorded
Financing Receivable Impaired [Line Items]
Unpaid Principal Balance		36		36		37
Recorded Investment		36		36		37
Related Allowance		0		0		0
Carrying Value		36		36		$ 37
Average Investment	[1]	36	17	36	17
Interest Income		$ 1	$ 0	$ 1	$ 0

[1] (1)Average recorded investment represents the average loan balances as of the beginning of period and all subsequent quarterly end of period balances.