Major Customers, Partnerships and Strategic Alliances - Agreement with Dow AgroSciences in Plant Agriculture - Additional Information (Detail) (Dow AgroSciences [Member], USD $)	1 Months Ended	3 Months Ended
	Oct. 31, 2005	Mar. 31, 2014	Mar. 31, 2013
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research program to develop laboratory research reagents	3 years
One-time license fee earned on exercise of option	$ 6,000,000
Royalty revenues	2,300,000
Percentage of royalties to be received from sublicensing	25.00%
Minimum license annual fees specific reckoning period	11 years
Fee due	25,300,000
Revenue attributable to research and development		0	0
Collaboration agreement related costs and expenses		0	0
Minimum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Annual fees	250,000
Maximum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Annual fees	3,000,000
License agreement terms [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty revenues	$ 4,000,000