Agreements - Debiopharm (Details) - USD ($)	1 Months Ended		3 Months Ended														6 Months Ended		12 Months Ended
	Dec. 31, 2017	May 31, 2017	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2016	Jun. 30, 2015
Collaborative Agreements disclosures
License and milestone fees			$ 29,580,000	$ 79,000	$ 31,080,000	$ 18,730,000	$ 5,076,000	$ 76,000	$ 76,000	$ 10,077,000	$ 10,692,000	$ 6,070,000	$ 5,086,000	$ 5,078,000	$ 41,417,000	$ 6,234,000	$ 5,152,000	$ 16,762,000	$ 79,469,000	$ 15,305,000	$ 26,915,000	$ 57,815,000
Research and development support			452,000	$ 650,000	$ 902,000	$ 1,478,000	1,427,000	$ 1,354,000	$ 1,335,000	$ 1,059,000	$ 848,000	$ 772,000	$ 708,000	$ 532,000	$ 832,000	$ 776,000	2,781,000	$ 1,620,000	3,482,000	5,175,000	$ 4,014,000	$ 2,848,000
Remaining arrangement consideration to be recognized as license revenue	$ 6,800,000		6,800,000				$ 7,100,000										$ 7,100,000		6,800,000	$ 7,100,000
Debiopharm
Collaborative Agreements disclosures
Payments received under collaboration agreement	4,500,000	$ 25,000,000
Potential milestone payments		5,000,000
License and milestone fees		29,700,000	29,500,000
Research and development support		300,000
Cumulative earnings	$ 30,000,000		$ 30,000,000																$ 30,000,000
Debiopharm | Phase 3 Clinical Trial
Collaborative Agreements disclosures
Potential milestone payments		$ 25,000,000