Collaboration and Financing Agreements - Additional Information (Detail) (USD $)	0 Months Ended	1 Months Ended	3 Months Ended		9 Months Ended			9 Months Ended	0 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended		9 Months Ended					3 Months Ended		9 Months Ended			0 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended	0 Months Ended			1 Months Ended			3 Months Ended		9 Months Ended			0 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended				1 Months Ended
	Jul. 18, 2011	Jul. 18, 2011	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Embedded Derivative Liabilities [Member]	Jul. 18, 2011 Healthcare Royalty Financing Agreement [Member]	Sep. 30, 2014 Healthcare Royalty Financing Agreement [Member]	Sep. 30, 2014 Healthcare Royalty Financing Agreement [Member]	Sep. 30, 2014 Healthcare Royalty Financing Agreement [Member] Embedded Derivative Liabilities [Member]	Sep. 30, 2013 Healthcare Royalty Financing Agreement [Member] Embedded Derivative Liabilities [Member]	Sep. 30, 2014 Healthcare Royalty Financing Agreement [Member] Embedded Derivative Liabilities [Member]	Sep. 30, 2013 Healthcare Royalty Financing Agreement [Member] Embedded Derivative Liabilities [Member]	May 16, 2014 Healthcare Royalty Financing Agreement [Member] Embedded Derivative Liabilities [Member]	Dec. 31, 2013 Healthcare Royalty Financing Agreement [Member] Embedded Derivative Liabilities [Member]	Jul. 18, 2011 Healthcare Royalty Financing Agreement [Member] Embedded Derivative Liabilities [Member]	Sep. 30, 2014 Healthcare Royalty Financing Agreement [Member] Common Stock Warrant Liabilities [Member]	Sep. 30, 2013 Healthcare Royalty Financing Agreement [Member] Common Stock Warrant Liabilities [Member]	Sep. 30, 2014 Healthcare Royalty Financing Agreement [Member] Common Stock Warrant Liabilities [Member]	Sep. 30, 2013 Healthcare Royalty Financing Agreement [Member] Common Stock Warrant Liabilities [Member]	Jul. 18, 2011 Healthcare Royalty Financing Agreement [Member] Common Stock Warrant Liabilities [Member]	Jul. 18, 2011 Healthcare Royalty Financing Agreement [Member] Scenario 1 [Member]	Sep. 30, 2014 Healthcare Royalty Financing Agreement [Member] Scenario 1 [Member]	Jul. 18, 2011 Healthcare Royalty Financing Agreement [Member] Scenario 2 [Member]	Sep. 30, 2014 Healthcare Royalty Financing Agreement [Member] Scenario 2 [Member]	Jul. 18, 2011 Healthcare Royalty Financing Agreement [Member] Scenario 3 [Member]	Sep. 30, 2014 Healthcare Royalty Financing Agreement [Member] Scenario 3 [Member]	Jul. 18, 2011 Minimum [Member] Healthcare Royalty Financing Agreement [Member] Scenario 1 [Member]	Jul. 18, 2011 Maximum [Member] Healthcare Royalty Financing Agreement [Member] Scenario 1 [Member]	Sep. 12, 2014 Daravita License Agreement [Member]	Oct. 31, 2013 Daravita License Agreement [Member]	May 31, 2012 Daravita License Agreement [Member]	Aug. 30, 2011 Daravita License Agreement [Member]	Sep. 30, 2014 Mallinckrodt LLC Co-Promotion Agreement [Member]	Sep. 30, 2013 Mallinckrodt LLC Co-Promotion Agreement [Member]	Sep. 30, 2014 Mallinckrodt LLC Co-Promotion Agreement [Member]	Sep. 30, 2013 Mallinckrodt LLC Co-Promotion Agreement [Member]	Mar. 31, 2014 Mallinckrodt LLC Co-Promotion Agreement [Member]	Jun. 27, 2013 Valeant Pharmaceuticals North America LLC Co-Promotion Agreement [Member]	Sep. 30, 2014 Valeant Pharmaceuticals North America LLC Co-Promotion Agreement [Member]	Sep. 30, 2013 Valeant Pharmaceuticals North America LLC Co-Promotion Agreement [Member]	Sep. 30, 2014 Valeant Pharmaceuticals North America LLC Co-Promotion Agreement [Member]	Sep. 30, 2013 Valeant Pharmaceuticals North America LLC Co-Promotion Agreement [Member]	Sep. 30, 2014 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Sep. 30, 2013 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Sep. 30, 2014 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Sep. 30, 2013 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Jul. 31, 2014 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Jul. 31, 2013 Astellas Pharma Us Inc Co Promotion Agreement [Member]	Nov. 30, 2007 Research and development Daravita License Agreement [Member]
Debt Instrument [Line Items]
Non Refundable Up Front Payment																																																				$ 500,000
Additional Payments On Achievement Of Series Of Milestones, Paid																																	2,750,000	1,000,000	750,000
Royalty Agreement Term																																15 years
Research and Development Arrangement, Automatic Term Extension																																3 years
Co-promotion agreement termination notice period																																									6 months
Agreement Termination Notice Period Net Sales Contingent																																									30 days
Agreement Termination Notice Period Change of Control Contingent																																									90 days
Sales Revenue, Services, Net																																										446,000	232,000	2,427,000	232,000
Incurred Service Fee Expenses																																				0	249,000	100,000	618,000
Tail payment liability related interest expense																																														0	40,000	87,000	327,000
Tail payment liability																																								491,000										1,218,000	2,032,000
Change in tail payment liability																																						321,000
CoPromotion Agreement Additional Term Increments																																									12 months
Debt instrument, outstanding									30,000,000
Common stock issued and sold to Healthcare Royalty, amount			141,000		141,000		139,000		1,500,000
Common stock issued and sold to Healthcare Royalty, shares			141,045,000		141,045,000		138,927,000		388,601
Common stock issued and sold to Healthcare Royalty, price per share									$ 3.86
Warrant exercisable to Healthcare Royalty, shares	225,000	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																								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 termination date										Mar. 31, 2018
Terminate payment base amount																									52,500,000
Borrowed internal rate of return																									19.00%		17.00%
Repayment of debt					40,041,000	0
Fair value of embedded derivatives																247,000	233,000
Aggregate net proceed from financing agreement									29,485,000
Financing discounts									476,000									605,000					790,000
Change in fair value								14,000				0	1,474,000	14,000	912,000				125,000	(8,000)	397,000	(43,000)
Loss on early extinguishment of debt			$ 0	$ 0	$ 1,254,000	$ 0