Related Parties - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 20, 2012
Related Party Transaction [Line Items]
Percentage of ownership interest acquired					18.00%
Fixed monthly charge to lab space and capital equipment used	$ 167,000	$ 735,000	$ 338,000	$ 1,139,000
Transitional Services Agreement [Member]
Related Party Transaction [Line Items]
Additional percentage of employee service payment			40.00%
TSA expenses recognized			500,000
Transitional Services Agreement [Member] | Research and development [Member]
Related Party Transaction [Line Items]
TSA expenses recognized			100,000
Transitional Services Agreement [Member] | General and administrative [Member]
Related Party Transaction [Line Items]
TSA expenses recognized			400,000
R&D Services Agreement [Member]
Related Party Transaction [Line Items]
Fixed monthly charge to lab space and capital equipment used			7,500
Due to Employees, fixed charges	500,000		500,000
Due to Employees, variable charges	250,000		250,000
Fixed charge per employee	$ 250,000		$ 250,000
Percentage of mark-up applied to fixed and variable charge			10.00%