Summary of Significant Accounting Policies - Property and Equipment Useful Lives (Details)	12 Months Ended
	Dec. 31, 2019
Laboratory equipment | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives (in years)	8 years
Laboratory equipment | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives (in years)	4 years
Software, office and computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives (in years)	3 years
Leasehold improvements, furniture, fixtures and fittings | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives (in years)	10 years
Leasehold improvements, furniture, fixtures and fittings | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives (in years)	5 years