Investments (Other Invested Assets - Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Carrying value of Tax Credits	$ 1,100	$ 1,300
Losses From Tax Credits	$ 226	$ 240	$ 257