Significant Accounting Policies - Schedule of Concentrations of Risk Percentage (Details) - Customer Concentration Risk	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Customer A | Revenue
Significant Accounting Policies [Line Items]
Concentration risk, percentage	12.70%	25.50%		26.40%
Customer A | Accounts Receivable, Net
Significant Accounting Policies [Line Items]
Concentration risk, percentage			32.70%
Customer B | Revenue
Significant Accounting Policies [Line Items]
Concentration risk, percentage		11.00%
Customer B | Accounts Receivable, Net
Significant Accounting Policies [Line Items]
Concentration risk, percentage					15.10%
Customer C | Accounts Receivable, Net
Significant Accounting Policies [Line Items]
Concentration risk, percentage					13.20%
Genentech, Inc. | Revenue
Significant Accounting Policies [Line Items]
Concentration risk, percentage	40.00%		43.60%