Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net loss (Numerator):
Net loss from continuing operations attributable to Echelon Corporation Stockholders	$ (7,226)	$ (3,510)	$ (13,058)	$ (13,202)
Net loss from discontinued operations attributable to Echelon Corporation Stockholders, net of income taxes	(1,962)	(3)	(8,715)	(385)
Net loss, basic and diluted	$ (9,188)	$ (3,513)	$ (21,773)	$ (13,587)
Shares (Denominator):
Weighted average common shares outstanding	43,507	43,184	43,367	43,039
Shares used in basic computation	43,507	43,184	43,367	43,039
Common shares issuable upon exercise of stock options (treasury stock method)	0	0	0	0
Shares used in diluted computation	43,507	43,184	43,367	43,039
Net loss per share:
Basic and diluted net loss per share from continuing operations attributable to Echelon Corporation Stockholders	$ (0.17)	$ (0.08)	$ (0.30)	$ (0.31)
Basic and diluted net loss per share from discontinued operations attributable to Echelon Corporation Stockholders	$ (0.05)	$ 0.00	$ (0.20)	$ (0.01)
Basic and diluted net loss attributable to Echelon Corporation Stockholders	$ (0.21)	$ (0.08)	$ (0.50)	$ (0.32)