Insurance (Fund Groupings) (Details) - Variable Annuity and Variable Life - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	$ 42,228	$ 50,307
Equity
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	19,579	23,213
Balanced
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	17,073	20,859
Bond
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	5,299	5,983
Money Market
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	$ 277	$ 252