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Represents the aggregate development costs.

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Direct expenses incurred, development costs.

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Payments for development cost.

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Represents the percentage of development costs related to joint development of any products for which the entity is responsible.

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Percentage of milestone payment on development cost.

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Percentage of patients to be enrolled.

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Product develpoment cost payable.

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Product develpoment cost payable upon enrollment of patients.

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Revenue recognition milestone method revenue expected.

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Stock repurchased price per share.

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Upfront payment paid.

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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.

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The noncurrent portion of deferred revenue amount as of balance sheet date. Deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized, and is not expected to be recognized in the next twelve months. 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.

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Costs incurred and are directly related to generating license revenue. Licensing arrangements include, but are not limited to, rights to use a patent, copyright, technology, manufacturing process, software or trademark.

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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A description of the factors that the entity considered in determining whether the milestone or milestones are substantive.

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Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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CO-DEVELOPMENT AND LICENSE AGREEMENT - Additional Information (Details) - USD ($) $ / shares in Units, shares in Millions					3 Months Ended		9 Months Ended
	Aug. 29, 2017	Jul. 06, 2016	Jul. 07, 2014	Feb. 13, 2014	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Co-development and license agreement
Deferred revenue					$ 41,175,600		$ 41,175,600
Research and development expense					8,956,468	$ 5,852,121	23,714,932	$ 13,941,283
Aggregate purchase price							389
Seltorexant \| Co-Development and License Agreement \| Phase 1b Clinical Trials \| Maximum
Co-development and license agreement
Share of aggregate development cost following completion of Phase 1b clinical trials and animal toxicology studies				$ 5,000,000
Seltorexant \| Co-Development and License Agreement \| Phase 2 Clinical Trials \| Maximum
Co-development and license agreement
Share of aggregate development cost following completion of Phase 1b clinical trials and animal toxicology studies				$ 24,000,000
Janssen \| Phase 3 Insomnia Trail
Co-development and license agreement
Milestone method payments							$ 40,000,000
Percentage of milestone payment on development cost							40.00%
Janssen \| Seltorexant \| Co-Development and License Agreement
Co-development and license agreement
Payment of license fee			$ 22,000,000
Percentage of development costs related to joint development of products				40.00%
Accrued collaborative expenses					0		$ 0		$ 2,500,000
Payment of development costs		$ 3,500,000					2,500,000	0
Direct expenses incurred		$ 300,000
Research and development expense					4,500,000	$ 3,500,000	11,200,000	$ 3,500,000
Janssen \| Seltorexant \| Amendment to Co-Development and License Agreement
Co-development and license agreement
Upfront payment	$ 30,000,000
Deferred revenue					41,200,000		$ 41,200,000
Accrued collaborative expenses	11,200,000
Revenue recognition, milestone method, factors							The $30 million payment and $11.2 million in previously accrued collaborative expenses, which were forgiven upon the effective date of the agreement, will be earned and recognized as revenue as the services are performed from the commencement of Phase 3 development to the completion of the development activities using the proportional performance method.
Janssen \| Seltorexant \| Amendment to Co-Development and License Agreement \| Upfront Payment
Co-development and license agreement
Deferred revenue					30,000,000		$ 30,000,000
Janssen \| Seltorexant \| Amendment to Co-Development and License Agreement \| Previously Accrued Collaborative Expenses
Co-development and license agreement
Deferred revenue					11,200,000		11,200,000
Janssen \| Seltorexant \| Amendment to Co-Development and License Agreement \| Phase 3 Insomnia Trail
Co-development and license agreement
Accrued collaborative expenses	11,200,000
Payment start of Phase	20,000,000
Payment upon enrollment of patients	$ 20,000,000
Percentage of patients to be enrolled	50.00%
Janssen \| Seltorexant \| Amendment to Co-Development and License Agreement \| Phase 3 Insomnia Trail \| Upfront Payment
Co-development and license agreement
Deferred revenue					30,000,000		30,000,000
Janssen \| Seltorexant \| Amendment to Co-Development and License Agreement \| Phase 3 Insomnia Trail \| Previously Accrued Collaborative Expenses
Co-development and license agreement
Deferred revenue					$ 11,200,000		$ 11,200,000
Johnson & Johnson Innovation-JJDC Inc
Co-development and license agreement
Stock repurchased	3.9
Stock repurchased price per share	$ 0.0001
Aggregate purchase price	$ 389