Research Agreements (Details)	3 Months Ended			3 Months Ended		1 Months Ended		3 Months Ended		1 Months Ended	3 Months Ended				1 Months Ended			3 Months Ended						1 Months Ended	3 Months Ended		1 Months Ended			3 Months Ended						1 Months Ended				1 Months Ended	3 Months Ended
	Mar. 31, 2013 USD ($)	Mar. 31, 2012 USD ($)	Dec. 31, 2012 USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement BA058-SC Phase 3 Clinical Study Maximum USD ($) item	Mar. 31, 2013 Clinical Trial Services Agreement BA058-SC Phase 3 Clinical Study Maximum EUR (€)	Feb. 28, 2013 Clinical Trial Services Agreement BA058-TD Phase 2 Clinical Study Nordic Series A-6 Maximum USD ($)	Feb. 28, 2013 Clinical Trial Services Agreement BA058-TD Phase 2 Clinical Study Nordic Series A-6 Maximum EUR (€)	Mar. 31, 2013 Clinical Trial Services Agreement Pass-through costs USD ($)	Mar. 31, 2012 Clinical Trial Services Agreement Pass-through costs USD ($)	Dec. 31, 2011 Clinical Trial Services Agreement BA058-SC Phase 3 Clinical Study item	Mar. 31, 2013 Clinical Trial Services Agreement BA058-SC Phase 3 Clinical Study Per patient costs for enrolled patients USD ($)	Mar. 31, 2012 Clinical Trial Services Agreement BA058-SC Phase 3 Clinical Study Per patient costs for enrolled patients USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement BA058-TD Phase 2 Clinical Study Per patient costs for enrolled patients USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement BA058-SC Phase 3 Extension Clinical Study Per patient costs for enrolled patients USD ($)	Feb. 28, 2013 Clinical Trial Services Agreement BA058-SC Phase 3 Extension Clinical Study Nordic Maximum USD ($)	Feb. 28, 2013 Clinical Trial Services Agreement BA058-SC Phase 3 Extension Clinical Study Nordic Maximum EUR (€)	Dec. 31, 2011 Clinical Trial Services Agreement First Amendment BA058-SC Phase 3 Clinical Study item	Mar. 31, 2013 Clinical Trial Services Agreement First Amendment BA058-SC Phase 3 Clinical Study United States item	Mar. 31, 2013 Clinical Trial Services Agreement First Amendment BA058-SC Phase 3 Clinical Study United States Maximum USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement First Amendment BA058-SC Phase 3 Clinical Study United States Maximum EUR (€)	Mar. 31, 2013 Clinical Trial Services Agreement First Amendment BA058-SC Phase 3 Clinical Study India item	Mar. 31, 2013 Clinical Trial Services Agreement First Amendment BA058-SC Phase 3 Clinical Study India Maximum USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement First Amendment BA058-SC Phase 3 Clinical Study India Maximum EUR (€)	Jun. 30, 2012 Clinical Trial Services Agreement Second Amendment BA058-SC Phase 3 Clinical Study item	Mar. 31, 2013 Clinical Trial Services Agreement Second Amendment BA058-SC Phase 3 Clinical Study USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement Second Amendment BA058-SC Phase 3 Clinical Study EUR (€)	Mar. 31, 2011 Clinical Trial Services Agreement Stock Issuance Agreement BA058-SC Phase 3 Clinical Study Nordic Series A-5 EUR (€)	May 31, 2011 Clinical Trial Services Agreement Stock Issuance Agreement BA058-SC Phase 3 Clinical Study Nordic Series A-5 Former Operating Company USD ($)	Mar. 29, 2011 Clinical Trial Services Agreement Stock Issuance Agreement BA058-SC Phase 3 Clinical Study Nordic Series A-5 Former Operating Company USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement Stock Issuance Agreement BA058-SC Phase 3 Clinical Study Nordic Series A-5 Maximum USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement Stock Issuance Agreement BA058-SC Phase 3 Clinical Study Nordic Series A-5 Maximum EUR (€)	Mar. 31, 2013 Clinical Trial Services Agreement Stock Issuance Agreement BA058-SC Phase 3 Clinical Study Nordic Series A-6 USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement Stock Issuance Agreement BA058-SC Phase 3 Clinical Study Nordic Series A-6 Minimum USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement Stock Issuance Agreement BA058-TD Phase 2 Clinical Study Nordic Series A-6 USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement Stock Issuance Agreement BA058-TD Phase 2 Clinical Study Nordic Series A-6 Minimum USD ($)	Feb. 28, 2013 Clinical Trial Services Agreement Stock Issuance Agreement BA058-SC Phase 3 Extension Clinical Study Nordic Maximum USD ($)	Feb. 28, 2013 Clinical Trial Services Agreement Stock Issuance Agreement BA058-SC Phase 3 Extension Clinical Study Nordic Maximum EUR (€)	Mar. 31, 2013 Clinical Trial Services Agreement Stock Issuance Agreement BA058-SC Phase 3 Extension Clinical Study Nordic Series A-6 USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement Stock Issuance Agreement BA058-SC Phase 3 Extension Clinical Study Nordic Series A-6 Minimum USD ($)	Feb. 28, 2013 Clinical Trial Services Agreement Letter of Intent BA058-TD Phase 2 Clinical Study Nordic Series A-6 Maximum USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement Letter of Intent BA058-SC Phase 3 Extension Clinical Study Nordic USD ($)	Mar. 31, 2013 Clinical Trial Services Agreement Letter of Intent BA058-SC Phase 3 Extension Clinical Study Nordic EUR (€)
Research Agreements
Number of countries where study was to be conducted										10														12
Number of additional countries where study will be conducted																	2
Number of additional study sites																		5			15
Final payments, number of euro-denominated installments				2	2
Final payments, number of U.S dollar-denominated installments				2	2
Amount of euro-denominated payments required over the course of Clinical Study				$ 52,700,000	€ 41,200,000	$ 4,600,000	€ 3,600,000								$ 5,800,000	€ 4,500,000			$ 1,500,000	€ 1,200,000		$ 919,804	€ 717,700		$ 4,700,000	€ 3,700,000
Amount of U.S. dollar-denominated payments required over the course of Clinical Study				3,200,000											579,495				143,369			289,663			205,540															257,853
Value of shares agreed to be purchased																											371,864
Purchase price per share of convertible preferred stock (in dollars per share)																													$ 8.142				$ 8.142		$ 8.142				$ 8.142
Shares sold																												64,430
Proceeds from issuance of shares																												525,154
Number of shares exchanged in the Merger																												6,443
Aggregate value of quarterly stock dividends, payable in shares						2,900,000																								47,200,000	36,800,000
Aggregate euro denominated value of quarterly stock dividends, payable in shares																																				5,800,000	4,500,000
Aggregate U.S. dollar value of quarterly stock dividends, payable in shares																																				300,000
Number of shares due to the counter party																																341,479		19,329				6,443
Number of shares due to the counter party after conversion of stock																																3,414,790		193,290				64,430
Fair value of liability																																14,300,000		800,000				300,000
Amount of liability reflected in accrued expenses and other current liabilities	16,626,000		8,740,000
Amount in accrued expenses resulting from services which are payable in stock																																1,700,000
Amount reflected in accrued expenses and other current liabilities resulting from services payable in cash																																9,600,000		300,000				300,000
Assets reflected in prepaid expenses and other current assets resulting from services which are payable in the form of a stock dividend																																		100,000				100,000
Amount of initial payments for Euro-denominated installments																																									1,000,000	806,468
Period for which research and development expense is recognized											20 months		9 months	9 months
Research and development expense	17,287,000	9,867,000						1,100,000	1,300,000		9,100,000	4,900,000	1,700,000	500,000
Reduction in amount of euro-denominated payments required over the course of clinical study																									$ 15,304	€ 11,941