Agreements - Novartis (Details)	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	May 31, 2018 item	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) item	Jun. 30, 2017 USD ($)	Dec. 31, 2010 USD ($) item
Collaborative Agreements disclosures
License and milestone fees		$ 1,321,000	$ 31,080,000	$ 12,861,000	$ 49,810,000
Novartis
Collaborative Agreements disclosures
Number of single-target licenses | item				5		6
Payments received under collaboration agreement						$ 45,000,000
License exercise fee						1,000,000
Potential milestone payment						$ 199,500,000
Number of licenses terminated | item	1
License and milestone fees		$ 978,000		$ 978,000