Derivative Instruments (Net Notional Volumes and Additional Disclosures) (Details) bbl in Millions, MWh in Millions, MMBTU in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021 USD ($) MWh MMBTU bbl	Dec. 31, 2020 USD ($) MWh MMBTU bbl
Interest Rate Swap [Member]
Derivative [Line Items]
Notional amount | $	$ 10,500	$ 10,500
Currency Swap [Member]
Derivative [Line Items]
Notional amount | $	$ 1,000	$ 1,000
Short [Member] | Commodity contract - Power [Member]
Derivative [Line Items]
Non-monetary net notional amount (in MWh) | MWh	104	90
Short [Member] | Commodity contract - Natural gas [Member]
Derivative [Line Items]
Non-monetary net notional amount (in MMBtu) | MMBTU	811	607
Short [Member] | Commodity contract - Oil [Member]
Derivative [Line Items]
Non-monetary net notional amount (in barrels) | bbl	(23)	(6)
FPL [Member] | Short [Member] | Commodity contract - Oil [Member]
Derivative [Line Items]
Non-monetary net notional amount (in barrels) | bbl	0	0
FPL [Member] | Long [Member] | Commodity contract - Power [Member]
Derivative [Line Items]
Non-monetary net notional amount (in MWh) | MWh	0	0
FPL [Member] | Long [Member] | Commodity contract - Natural gas [Member]
Derivative [Line Items]
Non-monetary net notional amount (in MMBtu) | MMBTU	241	87