Derivative Instruments (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Cumulative Foreign Currency Translation Gain Loss Recorded In Accumulated Other Comprehensive Income Loss For Net Investment In Foreign Operations Hedges	$ 139	$ 168
Counterparty Credit Derivative Exposure	19
Derivative Credit Risk Valuation Adjustment, Derivative Assets	70
Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax Future Reclass	6
Deferred Net Gains On Derivatives Expected to Be Reclassified To Investment Income	$ 1