Stock-Based Compensation - Performance-based Awards (Details) - shares	12 Months Ended
Dec. 31, 2017	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option shares approved		425,000
Performance-baseed awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option shares approved		200,000
Requisite service period	3 years
Performance-baseed awards \| Strategic arrangement milestone
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options unvested (in shares)	50,000
Vesting period	1 year
Performance-baseed awards \| Licensing arrangement milestone
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options unvested (in shares)	75,000
Vesting period	1 year
Performance-baseed awards \| Licensing arrangements related to oncology milestone
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options unvested (in shares)	75,000
Vesting period	1 year

Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Number of non-vested options outstanding.

+ References

No definition available.

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