Joint Venture	12 Months Ended
Dec. 31, 2017
Less Than Wholly Owned Subsidiary [Abstract]
Joint Venture	Joint Venture On March 23, 2012, the Company entered into an agreement with Holley Metering Limited (“Holley Metering”), a designer and manufacturer of energy meters in China, to create a joint venture, Zhejiang Echelon-Holley Technology Co., Ltd. (“Echelon-Holley”). The joint venture's intended focus was on the development and sales of smart energy products for China and rest-of-world markets. The Company has a 51% ownership interest in the joint venture and exercises controlling influence. Therefore, Echelon-Holley’s accounts are included in the Company’s consolidated financial statements as of December 31, 2017, and for the two years then ended. Holley Metering’s interests in Echelon-Holley’s net assets are reported in the noncontrolling interest in subsidiary on the consolidated balance sheet as of December 31, 2017 and 2016. Net loss attributable to the noncontrolling interest in Echelon-Holley was $0 during the years ended December 31, 2017 and 2016. As of December 31, 2017, Echelon and Holley Metering had contributed in cash a total of approximately $4,000,000 in Share Capital, as defined, to Echelon-Holley in proportion to their respective ownership interests. In connection with the decision to sell its Grid business announced in the third quarter of 2014, the Company undertook a process to sell the remaining net assets of the joint venture and recorded the net assets and liabilities of the joint venture at the lower of their carrying amount or fair value less cost to sell, and classified them as held for sale in the Company's consolidated balance sheet at December 31, 2014. The major classes of assets and liabilities that were classified as held for sale were inventory, deferred revenues and the related deferred costs of sales, and accrued liabilities. In addition, the net loss attributable to the non-controlling interests were presented as part of discontinued operations in the consolidated statement of operations for the year ended December 31, 2014. During the quarter ended September 30, 2015, the Company concluded that it would no longer pursue a sale, but would instead work with Holley Metering to shut the joint venture down. The remaining net assets of the joint venture were immaterial as of September 30, 2015.

Joint Venture

On March 23, 2012, the Company entered into an agreement with Holley Metering Limited (“Holley Metering”), a designer and manufacturer of energy meters in China, to create a joint venture, Zhejiang Echelon-Holley Technology Co., Ltd. (“Echelon-Holley”). The joint venture's intended focus was on the development and sales of smart energy products for China and rest-of-world markets. The Company has a 51% ownership interest in the joint venture and exercises controlling influence. Therefore, Echelon-Holley’s accounts are included in the Company’s consolidated financial statements as of December 31, 2017, and for the two years then ended. Holley Metering’s interests in Echelon-Holley’s net assets are reported in the noncontrolling interest in subsidiary on the consolidated balance sheet as of December 31, 2017 and 2016. Net loss attributable to the noncontrolling interest in Echelon-Holley was $0 during the years ended December 31, 2017 and 2016.

As of December 31, 2017, Echelon and Holley Metering had contributed in cash a total of approximately $4,000,000 in Share Capital, as defined, to Echelon-Holley in proportion to their respective ownership interests.

In connection with the decision to sell its Grid business announced in the third quarter of 2014, the Company undertook a process to sell the remaining net assets of the joint venture and recorded the net assets and liabilities of the joint venture at the lower of their carrying amount or fair value less cost to sell, and classified them as held for sale in the Company's consolidated balance sheet at December 31, 2014. The major classes of assets and liabilities that were classified as held for sale were inventory, deferred revenues and the related deferred costs of sales, and accrued liabilities. In addition, the net loss attributable to the non-controlling interests were presented as part of discontinued operations in the consolidated statement of operations for the year ended December 31, 2014.

During the quarter ended September 30, 2015, the Company concluded that it would no longer pursue a sale, but would instead work with Holley Metering to shut the joint venture down. The remaining net assets of the joint venture were immaterial as of September 30, 2015.