Debt (Details)	3 Months Ended
Mar. 31, 2017 USD ($)
FPL [Member] \| Other Long Term Debt, Variable [Member]
Debt Instrument [Line Items]
Principal Amount	$ 200
Interest Rate Terms	Variable
NEER [Member] \| Senior Secured Limited Recourse Term Loans, Variable [Member]
Debt Instrument [Line Items]
Principal Amount	$ 279
Interest Rate Terms	Variable
NEER [Member] \| Other Long Term Debt, Variable [Member]
Debt Instrument [Line Items]
Principal Amount	$ 200
Interest Rate Terms	Variable

Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_DebtInstrumentInterestRateTerms
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration