Allowance for Expected Credit Losses (Details) - Changes in the Allowance for Expected Credit Losses on Contractholder Receivables (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Credit Loss [Abstract]
Contractholder receivables (net of the allowance for expected credit losses), balance, beginning of period	$ 4,271	$ 4,634	$ 4,242	$ 4,599
Contractholder receivables (net of the allowance for expected credit losses), balance, end of period	4,016	4,314	4,016	4,314
Contractholder receivables, allowance for expected credit losses [Roll Forward]
Contractholder receivables, allowance for expected credit losses, beginning balance	19	20	19	20
Current period change for expected credit losses	0	2	0	2
Write-offs of uncollectible contractholder receivables	0	0	0	0
Contractholder receivables, allowance for expected credit losses, ending balance	$ 19	$ 22	$ 19	$ 22