Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended				1 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Silver Creek [Member]	Dec. 31, 2013 Silver Creek [Member]	May 31, 2014 Life Sciences Tax Incentive Program 2014 [Member] Employees	Sep. 30, 2014 Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Ownership interest percentage					64.00%	64.00%
Expected average maturities period of marketable securities classified as available-for-sale								3 months
Realized gains (losses) recognized on the sale or maturity of securities	$ 0	$ 0	$ 0	$ 0
Aggregate fair value	50,400,000		50,400,000
Other-than-temporary-impairment investments			0
Tax incentives awarded							600,000
State research and development tax credits monetized							$ 600,000
Number of incremental employees pledged to be hired							31
Performance period							5 years