Revenue Recognition (Details) - USD ($) $ in Millions		3 Months Ended	6 Months Ended
	Jan. 01, 2018	Jun. 30, 2018	Jun. 30, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers		$ 3,500	$ 6,800
FPL [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contracts with customers		2,900	5,500
NextEra Energy Resources [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue, remaining performance obligation		$ 680	$ 680
Sales Revenue, Net [Member] | FPL [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk, percentage			90.00%
Retained Earnings [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net reduction to retained earnings	$ 25