License and Collaboration Agreements - Additional Information (Detail) - USD ($)				1 Months Ended						3 Months Ended			18 Months Ended
	Sep. 23, 2014	Nov. 25, 2013	May. 05, 2011	Oct. 31, 2015	Aug. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Sep. 30, 2014	Mar. 31, 2016	Jun. 30, 2015	Mar. 31, 2015	Mar. 31, 2016	Dec. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenues, current										$ 45,097,000			$ 45,097,000	$ 50,137,000
Research and development expenses										32,882,000		$ 35,679,000
Deferred Revenue, Noncurrent										47,103,000			47,103,000	51,197,000
Baxalta [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proportional performance revenue recognition model										11,300,000		14,800,000
Substantive milestones										$ 0		0
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						$ 20,000,000
Deferred revenues										$ 88,217,000			88,217,000	97,365,000
Deferred revenues, current										45,100,000			45,100,000
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] | Research and Development Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum amount of milestone payments that can be received	100,000,000
Baxalta [Member] | License and Collaboration Agreements [Member] | Regulatory Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone license fee received													20,000,000
Maximum amount of milestone payments that can be received	520,000,000
Baxalta [Member] | License and Collaboration Agreements [Member] | Clinical Trials in Pancreatic Cancer [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone license fee received													62,500,000
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													20,000,000
Milestone license fee	$ 530,000,000
PharmaEngine [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront license fees paid			$ 10,000,000
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] | Sales Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum milestone payment obligation			$ 130,000,000
PharmaEngine [Member] | License and Collaboration Agreements [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payment						$ 11,000,000			$ 7,000,000
Research and development expenses										$ 100,000		$ 200,000
PharmaEngine [Member] | License and Collaboration Agreements [Member] | New Drug Application [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payment							$ 5,000,000
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										$ 3,900,000
Aggregate milestone payments eligible to receive, decrease								$ 400,000
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
Expected revenue recognition period begins after first sale of applicable product										10 years