Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2019 USD ($) numberOfReportingUnits	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jan. 01, 2019 USD ($)
Property, Plant and Equipment [Line Items]
Depreciation	$ 1,268,000	$ 155,000	$ 425,000
Goodwill	$ 6,234,000	6,234,000
Number of reporting units | numberOfReportingUnits	1
Goodwill impairment	$ 0	0	0
Indefinite-lived intangible asset	102,500,000	102,500,000
Asset impairment charges	0	0	1,116,000
Operating lease right-of-use assets	7,774,000			$ 8,641,000
Lease liability	$ 12,074,000
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	7 years
Topic 842
Property, Plant and Equipment [Line Items]
Operating lease right-of-use assets				8,641,000
Lease liability				$ 12,800,000
IPR&D
Property, Plant and Equipment [Line Items]
Indefinite-lived intangible asset	$ 102,500,000	102,500,000
Impairment of IPR&D	$ 0	$ 0	$ 0