Concentrations - Concentration Risk Percentage (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
One Original Equipment Manufacturer Customer | Revenues | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk percentage	52.00%	59.00%
One Original Equipment Manufacturer Customer | Accounts Receivable | Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk percentage	35.00%	1.00%
Supplier One | Material Purchases | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk percentage	17.00%	30.00%
Supplier Two | Material Purchases | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk percentage	11.00%
Supplier Three | Material Purchases | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk percentage	11.00%