Other Assets - Patent Licenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Finite-lived, intangible assets, net	$ 94,286	$ 4,568	$ 6,318
Finite-lived intangible assets, gross	119,203	17,204
Amortization on patents and tooling	965	786	391
Patent Licenses
Finite-Lived Intangible Assets [Line Items]
Finite-lived, intangible assets, net	2,400	3,200
Finite-lived intangible assets, gross	4,900
Patent Licenses | Cost of SaaS and License Revenue
Finite-Lived Intangible Assets [Line Items]
Amortization on patents and tooling	$ 700	600	$ 400
Patent Licenses | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (in years)	3 years
Patent Licenses | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life (in years)	11 years
Patent Licenses | Other Current Assets
Finite-Lived Intangible Assets [Line Items]
Finite-lived, intangible assets, net	$ 500	700
Patent Licenses | Other Assets
Finite-Lived Intangible Assets [Line Items]
Finite-lived, intangible assets, net	$ 1,900	$ 2,500