License and Collaboration Agreements - Additional Information (Detail) - USD ($)				1 Months Ended						3 Months Ended				9 Months Ended		24 Months Ended	35 Months Ended
	Sep. 23, 2014	Nov. 25, 2013	May 05, 2011	Jun. 30, 2016	Oct. 31, 2015	Aug. 31, 2015	Jul. 31, 2015	Jan. 31, 2015	Sep. 30, 2014	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015	Jun. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenues, current										$ 36,610,000				$ 36,610,000		$ 36,610,000	$ 36,610,000	$ 50,137,000
Other revenues										1,161,000				2,659,000
Research and development expenses										32,078,000		$ 37,763,000		105,956,000	$ 116,248,000
Deferred Revenue, Noncurrent										36,328,000				$ 36,328,000		36,328,000	36,328,000	51,197,000
Baxalta [Member] | License and Collaboration Agreements [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront license fee received									$ 100,000,000
Royalty for improved products														The Company is also entitled to tiered, escalating royalties ranging from sub-teen double digits to low twenties percentages of net sales of ONIVYDE in the Licensed Territory
Notice period of termination														180 days
Revenue recognized related to a substantive milestone payment					$ 47,500,000	$ 15,000,000					$ 10,000,000		$ 20,000,000
Deferred revenues										68,944,000				$ 68,944,000		68,944,000	68,944,000	97,365,000
Deferred revenues, current										36,600,000				36,600,000		36,600,000	36,600,000
Baxalta [Member] | License and Collaboration Agreements [Member] | Regulatory Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone license fee received																30,000,000
Maximum amount of milestone payments that can be received	$ 520,000,000
Baxalta [Member] | License and Collaboration Agreements [Member] | Research and Development Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone license fee received																62,500,000
Maximum amount of milestone payments that can be received	100,000,000
Baxalta [Member] | License and Collaboration Agreements [Member] | Sales Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum amount of milestone payments that can be received	250,000,000
Baxalta [Member] | License and Collaboration Agreements [Member] | Clinical Trials in Pancreatic Cancer [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration agreement costs	98,800,000
Baxalta [Member] | Non-Substantive Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone license fee received																62,500,000
Milestone license fee	90,000,000
Baxalta [Member] | Substantive Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone license fee received																30,000,000
Milestone license fee	$ 530,000,000
Baxalta [Member] | Commercial Supply Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Other revenues										1,200,000				2,400,000
PharmaEngine [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront license fees paid			$ 10,000,000
PharmaEngine [Member] | Sales Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum milestone payment obligation			130,000,000
PharmaEngine [Member] | Development and Regulatory Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum milestone payment obligation			$ 80,000,000
PharmaEngine [Member] | License and Collaboration Agreements [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payment				$ 10,000,000			$ 11,000,000		$ 7,000,000				$ 5,000,000
Research and development expenses												$ 100,000		10,100,000	$ 11,400,000
PharmaEngine [Member] | License and Collaboration Agreements [Member] | Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development expenses										100,000
PharmaEngine [Member] | Commercial Supply Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Other revenues										0				$ 300,000
Actavis [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Notice period of termination														90 days
Maximum amount of milestone and development payments that can be received		$ 15,100,000
Collaborative arrangement gross payments received																	4,000,000
Aggregate milestone payments eligible to receive, decrease								$ 400,000
Percentage of net profits on global sales of product														The Company will also receive a mid-twenties percentage of net profits on global sales of the Initial Product and any additional products.
Agreement expiration term respect to each product														10 years
Additional renewal term														2 years
Deferred Revenue, Noncurrent										$ 4,000,000				$ 4,000,000		$ 4,000,000	$ 4,000,000	$ 4,000,000
Expected revenue recognition period begins after first sale of applicable product														10 years