Long-term Obligation - Additional Information (Detail) (USD $)	3 Months Ended				1 Months Ended	3 Months Ended	12 Months Ended	19 Months Ended	1 Months Ended		3 Months Ended		3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Aug. 31, 2012 Financing Agreement with Biopharma	Mar. 31, 2014 Financing Agreement with Biopharma	Dec. 31, 2013 Financing Agreement with Biopharma	Mar. 31, 2014 Financing Agreement with Biopharma	Apr. 30, 2014 Financing Agreement with Biopharma Subsequent Events	Aug. 31, 2012 Financing Agreement with Biopharma Cash Required Under Debt Covenants	Mar. 31, 2014 Maximum Financing Agreement with Biopharma	Aug. 31, 2012 Maximum Financing Agreement with Biopharma	Mar. 31, 2014 Maximum Financing Agreement with Biopharma Quarterly Payment During 2014	Mar. 31, 2014 Maximum Financing Agreement with Biopharma Quarterly Payment During 2015	Mar. 31, 2014 Maximum Financing Agreement with Biopharma Quarterly Payment During 2016 and Later	Aug. 31, 2012 Minimum Financing Agreement with Biopharma Cash Required Under Debt Covenants
Debt Instrument [Line Items]
Proceeds from issuance of long-term obligation, net of cash paid for issuance costs					$ 30,000,000
Cumulative payments to be made under financing agreement												45,000,000
Aggregate payments to long-term obligations	995,000					2,020,000	1,025,000		1,000,000
Payment obligation based on a percentage of net product sales						20.00%					50.00%
Quarterly payment amount cap													3,000,000	3,750,000	0
Percentage of payments received for upfront, milestone or other contingent fees						20.00%		20.00%
Increase in percentage used to calculate long term payment obligations, description						The percentage used to calculate our payments to Biopharma would increase to 50 percent and any applicable payment caps would lapse if we (i) fail to provide Biopharma with certain information regarding our promotion and sales of Covered Products, (ii) do not devote a commercially reasonable amount of resources to the promotion and marketing of the Covered Products or (iii) violate the indebtedness covenant by incurring indebtedness greater than the sum of earnings before interest, taxes, depreciation and amortization, including such items as non-cash stock-based compensation, (EBITDA) for the four calendar quarters preceding such incurrence and, in each case, fail to cure within the applicable cure period.
Debt covenant, description										Pursuant to this agreement, we are not allowed to pay a dividend or other cash distribution, unless we will have cash and cash equivalents in excess of $50.0 million after such payment.
Cash and cash equivalents	43,618,000	81,460,000	54,877,000	93,032,000												50,000,000
Accretion of interest expense	1,044,000	1,115,000						7,100,000
Long term debt carrying value						35,100,000	35,100,000	35,100,000
Issuance costs capitalized						140,000		140,000
Unamortized issuance cost						$ 80,000	$ 87,000	$ 80,000