Summarized Financial Information of NEECH - Condensed Consolidating Statements of Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Comprehensive income (loss) attributable to NEE	$ 5,559	$ 3,009	$ 2,625
Reportable Legal Entities [Member] | NEE (Guarantor) [Member]
Condensed Financial Statements, Captions [Line Items]
Comprehensive income (loss) attributable to NEE	5,559	3,009	2,625
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Comprehensive income (loss) attributable to NEE	3,708	1,448	1,049
Consolidation, Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Comprehensive income (loss) attributable to NEE	$ (3,708)	$ (1,448)	$ (1,049)