Investments (Other Invested Assets - Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Carrying value of Tax Credits	$ 1,700	$ 1,800
Losses From Tax Credits	$ 257	$ 259	$ 167