Goodwill and Intangible Assets, Net - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Schedule of Goodwill
Goodwill beginning balance	$ 43,052	$ 43,116
Goodwill acquired during the period	5,494
Foreign exchange effects	105	(64)
Goodwill closing balance	48,651	$ 43,052
Residential Control Systems, Inc
Schedule of Goodwill
Goodwill closing balance	$ 5,500