Other Assets - Patent Licenses (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-lived, intangible assets, net	$ 72,181,000		$ 72,181,000		$ 79,067,000
Finite-lived intangible assets, gross	119,203,000		119,203,000		119,203,000
Amortization on patents and tooling			334,000	$ 512,000
Patent Licenses
Finite-Lived Intangible Assets [Line Items]
Finite-lived, intangible assets, net	2,700,000		2,700,000		2,900,000
Finite-lived intangible assets, gross	5,900,000		5,900,000
Patent Licenses | Cost of SaaS and License Revenue
Finite-Lived Intangible Assets [Line Items]
Amortization on patents and tooling	100,000	$ 200,000	200,000	300,000
Patent Licenses | Amortization and depreciation expense
Finite-Lived Intangible Assets [Line Items]
Amortization on patents and tooling	100,000	$ 0	$ 100,000	$ 0
Patent Licenses | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life			3 years
Patent Licenses | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life			12 years
Other Current Assets | Patent Licenses
Finite-Lived Intangible Assets [Line Items]
Finite-lived, intangible assets, net	500,000		$ 500,000		500,000
Other Assets | Patent Licenses
Finite-Lived Intangible Assets [Line Items]
Finite-lived, intangible assets, net	$ 2,200,000		$ 2,200,000		$ 2,400,000