Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives of Property and Equipment (Details)	9 Months Ended
	Sep. 30, 2018
Laboratory and Manufacturing Equipment | Minimum
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	2 years
Laboratory and Manufacturing Equipment | Maximum
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	8 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	Lesser of useful life or remaining lease term
Computer Equipment | Minimum
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	1 year
Computer Equipment | Maximum
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	5 years
Furniture and Fixtures | Minimum
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	3 years
Furniture and Fixtures | Maximum
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	5 years
Office Equipment | Minimum
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	3 years
Office Equipment | Maximum
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	5 years
Software | Minimum
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	3 years
Software | Maximum
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	5 years