Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Nov. 10, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	ENERGY FOCUS, INC/DE
Entity Central Index Key	0000924168
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		11,690,030