Essentialis, Inc. Acquisition - Additional Information (Details) - USD ($)	Mar. 07, 2017	Sep. 30, 2017
Business Acquisition [Line Items]
Share price (in usd per share)	$ 3.85
Essentialis, Inc. [Member]
Business Acquisition [Line Items]
Shares issued in acquisition (in shares)	3,783,388
Essentialis, Inc. [Member] \| Patents [Member]
Business Acquisition [Line Items]
Capitalized costs	$ 573,000
Legal fees	469,000
Printing fees	75,000
Accounting and other fees	29,000
Total intangible asset	$ 20,400,000
Essentialis, Inc. [Member] \| Indemnification Claims [Member]
Business Acquisition [Line Items]
Shares issued in acquisition (in shares)	182,675
Essentialis, Inc. [Member] \| Development Milestone [Member]
Business Acquisition [Line Items]
Shares issued in acquisition (in shares)	913,389
Probability of development success rate (percent)	15.30%
Revenue milestone in 2023		$ 100,000,000
Revenue milestone in 2025		$ 200,000,000
Essentialis, Inc. [Member] \| Earnout Payments [Member]
Business Acquisition [Line Items]
Contingent consideration	$ 30,000,000
Essentialis, Inc. [Member] \| Revenue Milestone One [Member]
Business Acquisition [Line Items]
WACC discount rate (percent)	30.00%
Essentialis, Inc. [Member] \| Revenue Milestone Two [Member]
Business Acquisition [Line Items]
WACC discount rate (percent)	21.00%

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