Non-Derivative 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		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gains (losses)	$ 354	$ 602	$ 605	$ (190)
FPL [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gains (losses)	$ 233	$ 395	$ 396	$ (96)