Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 17,000	$ 17,500	$ 15,400
Unbilled revenues	$ 392	389
FPL [Member] | Revenue Benchmark [Member]
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	90.00%
NEER [Member]
Disaggregation of Revenue [Line Items]
Revenue, remaining performance obligation	$ 825
FPL[Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	11,600	12,100	$ 11,800
Unbilled revenues	392	$ 389
Revenue, remaining performance obligation	$ 415