Financing Receivables (Allowance for Credit Losses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019	Dec. 31, 2019
Commercial loans [Member]
Rollforward of the allowance for loan losses
Beginning balance			$ 20	[1]	$ 20
Provisions			13
Write-offs		$ 0
Ending balance	$ 36	20	36		20
Accrued interest on commercial loans	11		11			$ 11
Commercial loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Rollforward of the allowance for loan losses
Beginning balance			3
Commercial loans [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Rollforward of the allowance for loan losses
Beginning balance			23
Syndicated loans [Member]
Rollforward of the allowance for loan losses
Loans purchased	84	39	134		94
Loans sold	$ 2	$ 11	$ 9		$ 32

[1] Prior to January 1, 2020, the allowance for credit losses was based on an incurred loss model that did not require estimating expected credit losses over the expected life of the asset.