Collaboration and Financing Agreements - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended		9 Months Ended			0 Months Ended	49 Months Ended			0 Months Ended			9 Months Ended	0 Months Ended	3 Months Ended		9 Months Ended						3 Months Ended			9 Months Ended		9 Months Ended		9 Months Ended			9 Months Ended		0 Months Ended	3 Months Ended		9 Months Ended		1 Months Ended		3 Months Ended		9 Months Ended					1 Months Ended		0 Months Ended	3 Months Ended	9 Months Ended
	Jul. 18, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Jul. 30, 2012 Oxford/SVB [Member]	Jul. 30, 2012 Oxford/SVB [Member]	Sep. 30, 2013 Oxford/SVB [Member]	Jun. 30, 2011 Oxford/SVB [Member]	Jul. 30, 2012 Oxford/SVB [Member] Revolving Credit Facility [Member]	Jun. 30, 2011 Oxford/SVB [Member] Revolving Credit Facility [Member]	Jun. 30, 2008 Loan And Security Agreement [Member]	Sep. 30, 2013 Embedded Derivative Liabilities [Member]	Jul. 18, 2011 Healthcare Royalty Financing Agreement [Member]	Sep. 30, 2013 Healthcare Royalty Financing Agreement [Member]	Sep. 30, 2012 Healthcare Royalty Financing Agreement [Member]	Sep. 30, 2013 Healthcare Royalty Financing Agreement [Member]	Sep. 30, 2012 Healthcare Royalty Financing Agreement [Member]	Sep. 30, 2013 Healthcare Royalty Financing Agreement [Member] Embedded Derivative Liabilities [Member]	Sep. 30, 2012 Healthcare Royalty Financing Agreement [Member] Embedded Derivative Liabilities [Member]	Dec. 31, 2012 Healthcare Royalty Financing Agreement [Member] Embedded Derivative Liabilities [Member]	Jul. 18, 2011 Healthcare Royalty Financing Agreement [Member] Embedded Derivative Liabilities [Member]	Sep. 30, 2013 Healthcare Royalty Financing Agreement [Member] Common Stock Warrant Liabilities [Member]	Sep. 30, 2012 Healthcare Royalty Financing Agreement [Member] Common Stock Warrant Liabilities [Member]	Jul. 18, 2011 Healthcare Royalty Financing Agreement [Member] Common Stock Warrant Liabilities [Member]	Sep. 30, 2013 Healthcare Royalty Financing Agreement [Member] Scenario 1 [Member]	Jul. 18, 2011 Healthcare Royalty Financing Agreement [Member] Scenario 1 [Member]	Sep. 30, 2013 Healthcare Royalty Financing Agreement [Member] Scenario 2 [Member]	Jul. 18, 2011 Healthcare Royalty Financing Agreement [Member] Scenario 2 [Member]	Sep. 30, 2013 Healthcare Royalty Financing Agreement [Member] Scenario 3 [Member]	Sep. 30, 2013 Minimum [Member] Oxford/SVB [Member]	Jul. 18, 2011 Minimum [Member] Healthcare Royalty Financing Agreement [Member] Scenario 1 [Member]	Sep. 30, 2013 Maximum [Member] Oxford/SVB [Member]	Jul. 18, 2011 Maximum [Member] Healthcare Royalty Financing Agreement [Member] Scenario 1 [Member]	Jun. 06, 2012 Mallinckrodt LLC Co-Promotion Agreement [Member]	Sep. 30, 2013 Mallinckrodt LLC Co-Promotion Agreement [Member]	Sep. 30, 2012 Mallinckrodt LLC Co-Promotion Agreement [Member]	Sep. 30, 2013 Mallinckrodt LLC Co-Promotion Agreement [Member]	Sep. 30, 2012 Mallinckrodt LLC Co-Promotion Agreement [Member]	Aug. 31, 2012 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Jul. 31, 2009 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Sep. 30, 2013 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Sep. 30, 2012 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Sep. 30, 2013 Astellas Pharma Us Inc Co Promotion Agreement [Member] tail_payments	Sep. 30, 2012 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Jul. 31, 2013 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Dec. 31, 2012 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Dec. 20, 2011 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Jul. 31, 2009 Astellas Pharma Us Inc Co Promotion Agreement [Member] Minimum [Member]	Jul. 31, 2009 Astellas Pharma Us Inc Co Promotion Agreement [Member] Maximum [Member]	Jun. 27, 2013 Valeant Pharmaceuticals North America LLC Co-Promotions Agreement [Member]	Sep. 30, 2013 Valeant Pharmaceuticals North America LLC Co-Promotions Agreement [Member]	Sep. 30, 2013 Valeant Pharmaceuticals North America LLC Co-Promotions Agreement [Member]
Debt Instrument [Line Items]
Company Entered Into Co Promotion Agreement																																													2009-07
Line of Credit Facility, Interest Rate During Period																																3.29%		7.29%
Co-Promotion Agreement, Renewal Period																																				6 months
Sales Period For Tail Payment																																				12 months
Co-promotion agreement termination notice period																																							60 days													6 months
Co-promotion agreement termination notice period for net sales contingency																																							60 days													30 days
Co-promotion agreement termination notice period for change of control contingency																																																				90 days
Service and other revenue		$ 271,000	$ 0	$ 398,000	$ 0																																																$ 232,000	$ 232,000
Incurred Service Fee Expenses																																					249,000	92,000	618,000	92,000					0	1,757,000
Additional term increments																																																				12 months
Non-refundable up-front payment																																										2,000,000
Milestone Payments																																										18,000,000
Service Fee Rate																																																		45.00%	55.00%
Deferred Agreement Payments																																										20,000,000
Deferred contract revenues																																												8,462,000
Number Of Annual Tail Payments																																													2
Tail payment liability related interest expense																																											40,000	93,000	327,000	414,000
Service fee reduction																																									1,500,000
Tail payment liability																																											1,090,000		1,090,000			2,795,000	5,291,000
Tail payment liability, first payment																																															2,000,000
Reduction to tail payment liability																																									742,000
Present value of the service fee receivable and tail payment																																																1,924,000
Recognized shared marketing expense																																													0	253,000
Debt instrument, outstanding													18,000,000		30,000,000
Common stock issued and sold to Healthcare Royalty, amount		108,000		108,000		101,000									1,500,000
Common stock issued and sold to Healthcare Royalty, shares		6,800,000		6,800,000												388,601		388,601
Common stock issued and sold to Healthcare Royalty, price per share		$ 1.66		$ 1.66												$ 3.86		$ 3.86
Warrant exercisable to Healthcare Royalty, shares	225,000
Warrant exercisable to Healthcare Royalty, price per share (usd per share)	$ 9.00																	$ 9.00
Term of warrant exercisable																		10 years
Revenue Interest Rate																0.50%		0.50%										5.00%		2.50%	0.50%		5.00%		5.75%
Net product sales amount received																		10,000,000									75,000,000		75,000,000		150,000,000
Fixed Debt Repayment Dates																		January 31, 2015, January 31, 2016 and January 31, 2017
Fixed Payments for Jan 31,2015																10,000,000		10,000,000
Fixed Payments for Jan 31,2016																10,000,000		10,000,000
Fixed Payments for Jan 31,2017																10,000,000		10,000,000
Agreement Expiration Date																																							2014-06-30						2012-03-31
Agreement termination date															Mar. 31, 2018
Intercreditor loan		25,000,000		25,000,000						25,000,000		10,000,000
Terminate payment base amount																		75,000,000									52,500,000		45,000,000
Borrowed internal rate of return																											19.00%		17.00%
Fair value of embedded derivatives																				80,000		992,000
Aggregate net proceed from financing agreement															29,485,000
Financing discounts															476,000								605,000			790,000
Other income (expense)		67,000	(1,421,000)	90,000	(1,379,000)											(8,000)	(23,000)	(43,000)	(65,000)
Change in fair value														(912,000)						912,000	166,000			1,474,000	(202,000)
Revolving credit facility										10,000,000
Term loan, interest rate										12.06%
Revolving credit facility, interest rate								equal to the greater of 3.29% above SVB’s prime rate or 7.29%
Percentage paid for unused portion of revolving credit facility								0.50%
Principal and interest repaid				0	40,051,000		19,492,000
Final Payment to Terminate Debt							1,200,000
Prepayment Premium to Terminate Debt							$ 400,000				$ 100,000
Percentage of principal as per payment premium									2.00%
Financing Agreement Termination Date																																													2013-06