Leases - Narrative (Details) ft² in Thousands, $ in Thousands		1 Months Ended	12 Months Ended
	Jun. 13, 2017 USD ($) ft²	Sep. 30, 2016 USD ($) ft²	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Lessee, Lease, Description [Line Items]
Termination period			1 year
Office lease term, months	123 months	129 months
Expected lease restoration charges		$ 3,100	$ 3,529	$ 3,391
Operating leases, rent expense				$ 4,200	$ 4,600
Office Building
Lessee, Lease, Description [Line Items]
Net rentable area | ft²	39
Monthly rental rate	$ 41
Expected lease restoration charges	700
Office Building and Laboratory
Lessee, Lease, Description [Line Items]
Area of office lease | ft²		64
Lease, period free of charge		9 months
Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term			1 year
Minimum | Office Building and Laboratory
Lessee, Lease, Description [Line Items]
Office lease, monthly rental rate		$ 144
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term			7 years
Maximum | Office Building
Lessee, Lease, Description [Line Items]
Monthly rental rate	$ 73
Maximum | Office Building and Laboratory
Lessee, Lease, Description [Line Items]
Office lease, monthly rental rate		$ 194