Goodwill and Intangible Assets, Net - Finite-Lived Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 04, 2015
Finite-Lived Intangible Assets, Net [Abstract]
Gross		$ 61,766	$ 55,170
Accumulated Amortization		(32,725)	(26,621)
Intangible assets, net		29,041	28,549
Finite-lived intangible assets, fully amortized, gross		$ 6,000	10,200
Intangible assets acquired, weighted average amortization period		6 years 9 months 18 days
Amortization expense		$ 6,956	6,274	$ 4,842
Cost of sales
Finite-Lived Intangible Assets, Net [Abstract]
Amortization expense		184	76	123
Selling, general and administrative expenses
Finite-Lived Intangible Assets, Net [Abstract]
Amortization expense		6,772	6,198	$ 4,719
Distribution rights
Finite-Lived Intangible Assets, Net [Abstract]
Gross		344	302
Accumulated Amortization		(165)	(119)
Intangible assets, net		$ 179	183
Intangible asset, estimated useful life		10 years
Patents
Finite-Lived Intangible Assets, Net [Abstract]
Gross		$ 13,250	12,038
Accumulated Amortization		(5,310)	(4,775)
Intangible assets, net		$ 7,940	7,263
Intangible asset, estimated useful life		10 years
Trademark and trade names
Finite-Lived Intangible Assets, Net [Abstract]
Gross		$ 2,786	2,400
Accumulated Amortization		(1,594)	(1,310)
Intangible assets, net		$ 1,192	1,090
Intangible asset, estimated useful life		10 years
Developed and core technology
Finite-Lived Intangible Assets, Net [Abstract]
Gross		$ 12,560	12,585
Accumulated Amortization		(6,071)	(4,068)
Intangible assets, net		6,489	8,517
Developed and core technology | Ecolink Intelligent Technology, Inc.
Finite-Lived Intangible Assets, Net [Abstract]
Intangible assets acquired					$ 9,080
Capitalized software development costs
Finite-Lived Intangible Assets, Net [Abstract]
Gross		142	142
Accumulated Amortization		(77)	(5)
Intangible assets, net		$ 65	137
Intangible asset, estimated useful life		2 years
Customer relationships
Finite-Lived Intangible Assets, Net [Abstract]
Gross		$ 32,534	27,703
Accumulated Amortization		(19,395)	(16,344)
Intangible assets, net		$ 13,139	11,359
Customer relationships | Ecolink Intelligent Technology, Inc.
Finite-Lived Intangible Assets, Net [Abstract]
Intangible assets acquired	$ 5,000				1,300
Intangible assets acquired, weighted average amortization period	10 years
Intangible asset, estimated useful life		5 years
Order backlog
Finite-Lived Intangible Assets, Net [Abstract]
Gross		$ 150	0
Accumulated Amortization		(113)	0
Intangible assets, net		$ 37	$ 0
Intangible asset, estimated useful life		1 year
Order backlog | Ecolink Intelligent Technology, Inc.
Finite-Lived Intangible Assets, Net [Abstract]
Intangible assets acquired	$ 200
Intangible assets acquired, weighted average amortization period	1 year
Trade name | Ecolink Intelligent Technology, Inc.
Finite-Lived Intangible Assets, Net [Abstract]
Intangible assets acquired	$ 400				$ 400
Intangible assets acquired, weighted average amortization period	8 years
Intangible asset, estimated useful life		7 years
Minimum
Finite-Lived Intangible Assets, Net [Abstract]
Intangible asset, estimated useful life		1 year
Minimum | Developed and core technology
Finite-Lived Intangible Assets, Net [Abstract]
Intangible asset, estimated useful life		5 years
Minimum | Developed and core technology | Ecolink Intelligent Technology, Inc.
Finite-Lived Intangible Assets, Net [Abstract]
Intangible asset, estimated useful life		4 years
Minimum | Customer relationships
Finite-Lived Intangible Assets, Net [Abstract]
Intangible asset, estimated useful life		10 years
Maximum
Finite-Lived Intangible Assets, Net [Abstract]
Intangible asset, estimated useful life		15 years
Maximum | Developed and core technology
Finite-Lived Intangible Assets, Net [Abstract]
Intangible asset, estimated useful life		15 years
Maximum | Developed and core technology | Ecolink Intelligent Technology, Inc.
Finite-Lived Intangible Assets, Net [Abstract]
Intangible asset, estimated useful life		14 years
Maximum | Customer relationships
Finite-Lived Intangible Assets, Net [Abstract]
Intangible asset, estimated useful life		15 years