Amount of deferred revenue recognized for transactions arising during the current reporting period. Deferred revenue is a liability as of the balance sheet date related to a revenue producing activity for which revenue has not yet been recognized. Generally, an Entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

No definition available.

Name:	us-gaap_DeferredRevenueAdditions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

License Agreement (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2011	Mar. 31, 2020	Mar. 31, 2019
Significant Agreements [Line Items]
License arrangement, deferred revenue, recognized		$ 0.0	$ 0.4
Up-front Payment [Member] \| Dainippon Sumitomo Pharma Co Ltd [Member]
Significant Agreements [Line Items]
License agreement payment	$ 15.0