Major Customers, Partnerships and Strategic Alliances - Agreement with Sigma-Aldrich Corporation - Additional Information (Detail) (Sigma-Aldrich Corporation [Member], USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended		3 Months Ended			1 Months Ended
	Oct. 31, 2009	Jul. 31, 2007	Mar. 31, 2014 License agreement terms [Member]	Mar. 31, 2013 License agreement terms [Member]	Oct. 31, 2009 License agreement terms [Member]	Oct. 31, 2009 Upfront license fee [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research program to develop laboratory research reagents		3 years
Upfront license fee	$ 20.0					$ 15.1
Common stock, valued	4.9
Public offering, common stock shares issued	636,133
Royalty revenues expected to be received					5.0
Reduced royalty rate	10.50%
Funding available under the amended agreement	25.0
Collaboration agreement related costs and expenses			$ 0	$ 0.1