License Agreement	3 Months Ended
Mar. 31, 2020
License Agreement [Abstract]
License Agreement	9. License Agreement In 2013, the Company licensed rights to tesetaxel in all major markets from Daiichi Sankyo Company, Limited (“Daiichi Sankyo”), the original inventor of the product. Under the Daiichi Sankyo license agreement, the Company is obligated to use commercially reasonable efforts to develop and commercialize tesetaxel in the following countries: France, Germany, Italy, Spain, the United Kingdom and the U.S. The Company is required to make aggregate future milestone payments of up to $31.0 million, contingent on attainment of certain regulatory milestones. Additionally, the Company is obligated to pay Daiichi Sankyo a tiered royalty that ranges from the low to high single digits, depending on annual net sales of tesetaxel.

The entire disclosure for collaborative arrangements in which the entity is a participant, including a) information about the nature and purpose of such arrangements; b) its rights and obligations thereunder; c) the accounting policy for collaborative arrangements; and d) the income statement classification and amounts attributable to transactions arising from the collaborative arrangement between participants.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 808
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6931272&loc=SL5834143-161434

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 808
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6931272&loc=SL5834143-161434

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 808
-URI http://asc.fasb.org/topic&trid=5833765

Name:	us-gaap_CollaborativeArrangementDisclosureTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration