Concentration of Credit Risk (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Cash and cash equivalents | Concentration of credit risk
Concentration Risk [Line Items]
Risk concentration	98.00%		82.00%
Net accounts receivable | Customer concentration | Customer A
Concentration Risk [Line Items]
Risk concentration			24.00%
Net accounts receivable | Customer concentration | Customer B
Concentration Risk [Line Items]
Risk concentration	18.00%
Net accounts receivable | Customer concentration | Customer C
Concentration Risk [Line Items]
Risk concentration	15.00%
Net accounts receivable | Customer concentration | Customer D
Concentration Risk [Line Items]
Risk concentration	11.00%
Total revenue | Customer concentration | Customer A
Concentration Risk [Line Items]
Risk concentration	11.00%	34.00%
Total revenue | Customer concentration | Customer B
Concentration Risk [Line Items]
Risk concentration		55.00%
Total revenue | Customer concentration | Customer C
Concentration Risk [Line Items]
Risk concentration	26.00%
Total revenue | Customer concentration | Customer D
Concentration Risk [Line Items]
Risk concentration	12.00%
Total revenue | Customer concentration | Customer E
Concentration Risk [Line Items]
Risk concentration	14.00%