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	$ 93,741	$ 111,869
Balanced
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	60,040	56,979
Equity
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	25,344	47,571
Bond
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	8,339	6,662
Money Market
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	$ 18	$ 657