Fair Value Measurements (Reconciliation of Changes in the Fair Value) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Realized and unrealized gains (losses): [Abstract]
Fair value based on significant unobservable inputs, ending balance	$ 1,231	$ 650	$ 1,231	$ 650
FPL [Member]
Realized and unrealized gains (losses): [Abstract]
Fair value based on significant unobservable inputs, ending balance	(13)	0	(13)	0
Derivative Financial Instruments, Net [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value based on significant unobservable inputs, beginning balance	844	625	647	566
Realized and unrealized gains (losses): [Abstract]
Included in earnings	513	37	692	52
Included in other comprehensive income	(2)	7	1	4
Included in regulatory assets and liabilities	1	2	(1)	0
Purchases	43	61	67	103
Settlements	(81)	(55)	(119)	(7)
Issuances	(37)	(28)	(51)	(61)
Impact of adoption of new revenue standard			0	(30)
Transfers in	0	1	0	1
Transfers out	(50)	0	(5)	22
Fair value based on significant unobservable inputs, ending balance	1,231	650	1,231	650
Gains (losses) included in earnings attributable to the change in unrealized gains (losses) relating to derivatives held at the reporting date	487	57	568	38
Realized and unrealized gains (losses) reflected in operating revenues	509	44	703	71
Unrealized gains (losses) reflected in operating revenues related to derivatives still held at the reporting date	482	64	578	57
Derivative Financial Instruments, Net [Member] | FPL [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value based on significant unobservable inputs, beginning balance	(16)	(2)	(36)	0
Realized and unrealized gains (losses): [Abstract]
Included in earnings	0	0	0	0
Included in other comprehensive income	0	0	0	0
Included in regulatory assets and liabilities	1	2	(1)	0
Purchases	0	0	0	0
Settlements	2	(1)	22	(1)
Issuances	0	0	0	0
Impact of adoption of new revenue standard			0	0
Transfers in	0	1	0	1
Transfers out	0	0	2	0
Fair value based on significant unobservable inputs, ending balance	(13)	0	(13)	0
Gains (losses) included in earnings attributable to the change in unrealized gains (losses) relating to derivatives held at the reporting date	0	$ 0	0	$ 0
Fair Value, Inputs, Level 3 [Member] | Interest Rate Swap [Member] | NextEra Energy Resources [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 145		$ 145