Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Net loss (Numerator):
Net loss from continuing operations attributable to Echelon Corporation Stockholders	$ (1,424)	$ (2,560)
Net loss from discontinued operations attributable to Echelon Corporation Stockholders, net of income taxes	0	(1,413)
Net loss attributable to Echelon Corporation Stockholders	$ (1,424)	$ (3,973)
Shares (Denominator):
Weighted average common shares outstanding	43,950	43,264
Shares used in basic computation		43,264
Common shares issuable upon exercise of stock options (treasury stock method)	0	0
Shares used in diluted computation	43,950	43,264
Net loss per share:
Basic and diluted net loss per share from continuing operations attributable to Echelon Corporation Stockholders	$ (0.03)	$ (0.06)
Basic and diluted net loss per share from discontinued operations attributable to Echelon Corporation Stockholders	$ 0.00	$ (0.03)
Basic and diluted net loss attributable to Echelon Corporation Stockholders	$ (0.03)	$ (0.09)