Long-Term Obligations - Additional Information (Detail) (USD $)	1 Months Ended	9 Months Ended	12 Months Ended	1 Months Ended				9 Months Ended			9 Months Ended		12 Months Ended		9 Months Ended					1 Months Ended
	Jan. 31, 2012 sqft	Sep. 30, 2013	Dec. 31, 2012	Jan. 31, 2012 Maximum	Jan. 31, 2012 Extended Term	Sep. 30, 2013 Healthcare Royalty Partners	Dec. 31, 2012 Healthcare Royalty Partners	Sep. 30, 2013 Healthcare Royalty Partners Tranche A and Tranche B Loans (Original Loan)	Sep. 30, 2013 Healthcare Royalty Partners Tranche A and Tranche B Loans (Original Loan) Phase 3 Trials	Sep. 30, 2013 Healthcare Royalty Partners Tranche A and Tranche B Loans (Original Loan) Group Two	Sep. 30, 2013 Healthcare Royalty Partners Tranche A and Tranche B Loans (Original Loan) Group Two Minimum	Sep. 30, 2013 Healthcare Royalty Partners Refinanced Term Loan Tranche A Loan Legal Fee	Dec. 31, 2011 Healthcare Royalty Partners Refinanced Term Loan Tranche A Loan Second Affiliated	Sep. 30, 2013 Healthcare Royalty Partners Refinanced Term Loan Tranche A Loan Second Affiliated	Sep. 30, 2013 Healthcare Royalty Partners Refinanced Term Loan Tranche B Loan Second Affiliated	Sep. 30, 2013 Healthcare Royalty Partners LFRP	Sep. 30, 2013 Healthcare Royalty Partners LFRP Tranche A and Tranche B Loans (Original Loan)	Sep. 30, 2013 Healthcare Royalty Partners LFRP Tranche A Loan	Sep. 30, 2013 Healthcare Royalty Partners LFRP Tranche B Loan	Jun. 30, 2012 Silicon Valley Bank Equipment lease	Sep. 30, 2013 Silicon Valley Bank Equipment lease	Jun. 30, 2012 Silicon Valley Bank Equipment lease Negotiable Order of Withdrawal Accounts
Debt Disclosure [Line Items]
Secured Loan																$ 61,700,000		$ 84,500,000	$ 22,800,000
Debt maturity date																	2018-08
Interest rate													13.00%				12.00%
Debt instrument maturity date								Sep. 30, 2016
Percentage of required payment for partial repayment of debt								90.00%	75.00%	25.00%
Annual net LFRP receipts amount used as a basis for repayment of loan									15,000,000		15,000,000
Principal amount of Loan																		21,700,000	58,800,000
Proceed from unsecured loan													20,000,000		57,600,000
Effective interest rate														12.60%
Decrease in note payable		149,000	198,000									193,000
Loan principal balance						84,500,000	81,200,000
Fair value of note payable		84,500,000
Line of credit, maximum borrowing capacity																				3,000,000
Interest on lease																				6.00%
Line of credit																						1,400,000
Line of credit term																				3 years
Line of credit, outstanding balance																					1,000,000
Rentable square feet of office and laboratory facilities	45,000
Lease agreement term	10 years				5 years
Aggregate minimum lease commitment over payment lease term	15,000,000
Letter of Credit given to landlord to secure lease obligation	1,100,000
Tenant improvement allowance				2,600,000
Capitalized leasehold improvements		$ 4,510,000	$ 4,502,000