Identified Intangible Assets and Goodwill, Net Schedule of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Goodwill, balance at January 1, 2018	$ 35,477	$ 30,305
Goodwill, acquisitions	2,840	5,131	$ 817
Goodwill, translation and other adjustments	(346)	41
Goodwill, balance at December 31, 2018	37,971	35,477	30,305
Utility
Goodwill [Roll Forward]
Goodwill, balance at January 1, 2018	3,424	3,424
Goodwill, acquisitions	1,487	0
Goodwill, translation and other adjustments	0	0
Goodwill, balance at December 31, 2018	4,911	3,424	3,424
Residential and Commercial
Goodwill [Roll Forward]
Goodwill, balance at January 1, 2018	32,053	26,881
Goodwill, acquisitions	1,353	5,131
Goodwill, translation and other adjustments	(346)	41
Goodwill, balance at December 31, 2018	$ 33,060	$ 32,053	$ 26,881