Financing Receivables (Credit Quality Information Text) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
90 days or more past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonperforming loans	$ 31	$ 25
Syndicated loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	560	543
Syndicated loans [Member] | 90 days or more past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonperforming loans	0	1
Commercial mortgage loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonperforming loans	$ 0	0
Percentage of commercial mortgage loans with highest risk rating less than %	1.00%
Total loans, gross	$ 2,805	$ 2,797