Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 9,590	$ 9,983	$ 9,363	$ 9,868	$ 9,647	$ 9,178	$ 8,981	$ 10,924	$ 38,804	[1]	$ 38,730	[1]	$ 45,857	[1]
Cost of Revenue	4,093	4,370	3,821	4,244	4,316	4,180	3,784	4,538	16,528	[2]	16,818	[2]	18,015	[2]
Gross profit	5,497	5,613	5,542	5,624	5,331	4,998	5,197	6,386	22,276		21,912		27,842
Product development	2,341	2,454	2,340	2,612	2,286	2,305	2,170	2,749	9,747	[2]	9,510	[2]	10,922	[2]
Sales and marketing	1,602	1,848	2,194	2,188	2,498	2,160	2,265	2,175	7,832	[2]	9,098	[2]	9,061	[2]
General and administrative	1,694	2,547	2,187	2,821	2,847	3,538	3,579	3,770	9,249	[2]	13,734	[2]	14,644	[2]
Goodwill impairment charges	5,698	0	0	0	0	0	0	0	5,698		0		0
Lease termination charges	0	0	3,337	0	0	0	0	0	3,337		0		0
Loss on write down of property, equipment and other	0	0	0	0	0	4,409	0	0	0		4,409		0
Restructuring charges	0	0	0	0	164	227	0	0	0		391		2,254
Total operating expenses	11,335	6,849	10,058	7,621	7,795	12,639	8,014	8,694	35,863		37,142		40,333
Loss from operations	(5,838)	(1,236)	(4,516)	(1,997)	(2,464)	(7,641)	(2,817)	(2,308)	(13,587)		(15,230)		(12,491)
Interest and other income (expense), net	227	184	(458)	838	269	719	(69)	11	791		930		(702)
Interest Expense, Other	(2)	(5)	(128)	(252)	(261)	(271)	(280)	(288)	(387)		(1,100)		(1,235)
Loss before provision for income taxes	(5,613)	(1,057)	(5,102)	(1,411)	(2,456)	(7,193)	(3,166)	(2,585)	(13,183)		(15,400)		(14,428)
Income tax expense	(14)	(10)	61	13	97	33	106	(25)	50		211		311
Income (Loss) from Continuing Operations Attributable to Parent	(5,599)	(1,047)	(5,163)	(1,424)	(2,553)	(7,226)	(3,272)	(2,560)					(14,739)
Net loss from discontinued operations, net of income taxes	0	0	0	0	0	(2,141)	(5,579)	(1,530)	0	[2]	(9,250)	[2]	(3,679)	[2]
Net loss from discontinued operations attributable to non controlling interest, net of income taxes	0	0	0	0	0	179	239	117	0		535		808
Net loss from discontinued operations attributable to Echelon Corporation Stockholders, net of income taxes	0	0	0	0	0	(1,962)	(5,340)	(1,413)	0		(8,715)		(2,871)
Net Income (Loss) Attributable to Parent	$ (5,599)	$ (1,047)	$ (5,163)	$ (1,424)	$ (2,553)	$ (9,188)	$ (8,612)	$ (3,973)	$ (13,233)		$ (24,326)		$ (17,610)
Basic and diluted net loss per share from continuing operations attributable to Echelon Corporation Stockholders	$ (1.27)	$ (0.24)	$ (1.17)	$ (0.32)	$ (0.58)	$ (1.66)	$ (0.76)	$ (0.59)	$ (3.00)		$ (3.59)		$ (3.42)
Basic and diluted net loss per share from discontinued operations attributable to Echelon Corporation Stockholders	0.00	0.00	0.00	0.00	0.00	(0.45)	(1.23)	(0.33)	0.00		(2.00)		(0.67)
Basic and diluted net loss per share attributable to Echelon Corporation Stockholders	$ (1.27)	$ (0.24)	$ (1.17)	$ (0.32)	$ (0.58)	$ (2.11)	$ (1.99)	$ (0.92)	$ (3.00)		$ (5.59)		$ (4.09)
Weighted Average Number of Shares Outstanding, Basic	4,416	4,413	4,406	4,395	4,390	4,351	4,333	4,326	4,409		4,350		4,309
Weighted Average Number of Shares Outstanding, Diluted	4,416	4,413	4,406	4,395	4,390	4,351	4,333	4,326	4,409		4,350		4,309

[1] Includes related party amounts of $4,909 in 2015, $2,993 in 2014, and $7,363 in 2013. See Note 14 for additional information on related party transactions.

[2] See Note 8 for summary of amounts included representing stock-based compensation expense.