Insurance (Fund Groupings) (Details) - Variable Annuity and Variable Life - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	$ 50,307	$ 47,284	[1]
Equity
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	23,213	21,169
Balanced
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	20,859	20,070
Bond
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	5,983	5,827
Money Market
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings	$ 252	218
Restatement Adjustment
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fund Groupings		$ 6,700

[1] $6.7 billion