Commitments and Contingencies - Additional Information (Details)			3 Months Ended	6 Months Ended
	Apr. 16, 2018 USD ($)	Aug. 26, 2008	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($) lease	May 31, 2019 ft²	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jun. 30, 2018 USD ($)
Commitments And Contingencies [Line Items]
Number of leases | lease				2
Assets under capital lease			$ 400,000	$ 400,000
Capital lease interest expense obligation			100,000	100,000
Gross fixed assets for capital leases								$ 300,000
Increase ROU asset				145,000
Increase lease liability				$ 127,000
Service contract term				3 years
ROU asset			2,494,000	$ 2,494,000		$ 1,566,000
Operating Lease Obligations			2,621,000	2,621,000
Rent, lease amortization and interest expense			100,000	200,000
Right-of-use assets			$ 1,025,000	$ 2,592,000
Weighted average discount rate			9.00%	9.00%
Remaining term on lease liabilities			6 years 2 months 12 days	6 years 2 months 12 days
Initial term of agreement	3 years
Bio Valve
Commitments And Contingencies [Line Items]
Upfront license, signing fees and development milestone payments		9.00%
Upfront license, signing fees and development milestone payments, certain circumstances		10.00%
Amounts owed			$ 0	$ 0			$ 0
Integration fee
Commitments And Contingencies [Line Items]
Agreement payment	$ 100,000
Annual maintenance fee
Commitments And Contingencies [Line Items]
Agreement payment	$ 100,000
First Amendment to the Marlborough Massachusetts lease
Commitments And Contingencies [Line Items]
Square feet | ft²					4,076
Increase ROU asset			800,000
Increase lease liability			800,000
Right-of-use assets			1,000,000	2,600,000
Embedded lease
Commitments And Contingencies [Line Items]
ROU asset			200,000	200,000
Operating Lease Obligations			$ 200,000	$ 200,000