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Collaboration, License and Purchase Agreements - Narrative (Details) - USD ($)		1 Months Ended			3 Months Ended	12 Months Ended
	Oct. 24, 2014	Oct. 31, 2016	May 31, 2014	Jul. 31, 2011	Dec. 31, 2016	Dec. 31, 2017
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Payments to acquire global rights to preclinical development program		$ 1,500,000
Endo Asset Purchase Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Term of agreement			8 years
Durect Development and License Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Minimum future milestone payments				$ 103,000,000.0
Aradigm Corporation Asset Purchase Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalty rate (percent)						3.00%
Brabant Pharma Limited [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Aggregate amount of contingent liabilities	$ 95,000,000
Regulatory Milestones [Member] \| Brabant Pharma Limited [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Aggregate amount of contingent liabilities	50,000,000
Sales Milestones [Member] \| Brabant Pharma Limited [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Aggregate amount of contingent liabilities	$ 45,000,000
Sumavel DosePro [Member] \| Prepaid Royalties [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Impairment of prepaid royalties					$ 2,000,000