In-License Agreements - Narrative (Details) - USD ($)			6 Months Ended
	Aug. 06, 2017	Mar. 10, 2016	Jun. 30, 2020
2017 Mayo License Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Non-refundable upfront fee	$ 200,000
Milestone payments upon achievement of certain development, regulatory, and commercial events			$ 200,000
Amount due under license agreement			0
2017 Mayo License Agreement | Maximum
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestone payments upon achievement of certain development, regulatory, and commercial events	$ 56,000,000.0
2016 University of Chicago Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestone payments upon achievement of certain development, regulatory, and commercial events		$ 60,900,000
Milestone payments for development and commercialization of licensed products			$ 400,000
2016 University of Chicago Agreement | Maximum
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Non-refundable upfront fee		$ 500,000