Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended									12 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Revenues		$ 7,498	$ 8,179	$ 8,061	$ 8,647	$ 9,590	$ 9,983	$ 9,363	$ 9,868		$ 32,385	[1]	$ 38,804	[1]	$ 38,730	[1]
Cost of Revenue		3,375	3,707	3,415	3,805	4,093	4,370	3,821	4,244		14,302	[2]	16,528	[2]	16,818	[2]
Gross profit		4,123	4,472	4,646	4,842	5,497	5,613	5,542	5,624		18,083		22,276		21,912
Product development		2,119	1,963	1,985	2,193	2,341	2,454	2,340	2,612		8,260	[2]	9,747	[2]	9,510	[2]
Sales and marketing		1,638	1,570	1,679	1,302	1,602	1,848	2,194	2,188		6,189	[2]	7,832	[2]	9,098	[2]
General and administrative		1,782	2,087	2,197	2,011	1,694	2,547	2,187	2,821		8,077	[2]	9,249	[2]	13,734	[2]
Goodwill impairment charges		0	0	0	0	5,698	0	0	0		0		5,698		0
Lease termination charges		0	0	0	0	0	0	3,337	0		0		3,337		0
Loss on write down of property, equipment and other										$ 4,409	0		0		4,409
Restructuring charges		286	0	0	0	0	0	0	0		286		0		391
Total operating expenses		5,825	5,620	5,861	5,506	11,335	6,849	10,058	7,621		22,812		35,863		37,142
Loss from operations		(1,702)	(1,148)	(1,215)	(664)	(5,838)	(1,236)	(4,516)	(1,997)		(4,729)		(13,587)		(15,230)
Interest and other income (expense), net		567	(57)	503	(205)	227	184	(458)	838		808		791		930
Interest Expense, Other		0	0	0	0	(2)	(5)	(128)	(252)		0		(387)		(1,100)
Loss before provision for income taxes		(1,135)	(1,205)	(712)	(869)	(5,613)	(1,057)	(5,102)	(1,411)		(3,921)		(13,183)		(15,400)
Income tax expense		102	23	51	6	(14)	(10)	61	13		182		50		211
Income (Loss) from Continuing Operations Attributable to Parent															(15,611)
Net loss from discontinued operations, net of income taxes	[2]										0		0		(9,250)
Net loss from discontinued operations attributable to non controlling interest, net of income taxes											0		0		535
Net loss from discontinued operations attributable to Echelon Corporation Stockholders, net of income taxes											0		0		(8,715)
Net Income (Loss) Attributable to Parent		$ (1,237)	$ (1,228)	$ (763)	$ (875)	$ (5,599)	$ (1,047)	$ (5,163)	$ (1,424)		$ (4,103)		$ (13,233)		$ (24,326)
Basic and diluted net loss per share from continuing operations attributable to Echelon Corporation Stockholders		$ (0.28)	$ (0.28)	$ (0.17)	$ (0.20)	$ (1.27)	$ (0.24)	$ (1.17)	$ (0.32)		$ (0.93)		$ (3.00)		$ (3.59)
Basic and diluted net loss per share from discontinued operations attributable to Echelon Corporation Stockholders											0.00		0.00		(2.00)
Basic and diluted net loss per share attributable to Echelon Corporation Stockholders											$ (0.93)		$ (3.00)		$ (5.59)
Weighted Average Number of Shares Outstanding, Basic		4,432	4,431	4,420	4,417	4,416	4,413	4,406	4,395		4,425		4,409		4,350
Weighted Average Number of Shares Outstanding, Diluted		4,432	4,431	4,420	4,417	4,416	4,413	4,406	4,395		4,425		4,409		4,350

[1] Includes related party amounts of $1,313, $4,909, and $2,993 in 2016, 2015, and 2014, respectively. See Note 14 for additional information on related party transactions.

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