Fair Value Measurements (Unrealized Gains (Losses) Recognized On Equity Securities Still Held at The Reporting Date) (Details) - Equity Securities [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gains (losses)	$ 223	$ 21	$ 65	$ 500
FPL [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gains (losses)	$ 129	$ 18	$ 50	$ 327