Commitments - Additional Information (Detail) (USD $)	9 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Other Lease Agreement [Member] Laboratory Equipment, Computer Equipment and Computer Software Received [Member]	Sep. 30, 2013 Other Lease Agreement [Member] Laboratory Equipment, Computer Equipment and Computer Software Received [Member]	Sep. 30, 2013 Other Lease Agreement [Member] Laboratory Equipment, Computer Software and Furniture Equipment Not Yet Received [Member]	Sep. 30, 2013 Other Lease Agreement [Member] Laboratory Equipment, Computer Software and Furniture Equipment Not Yet Received [Member]	Sep. 30, 2013 Minimum [Member] Other Lease Agreement [Member] Laboratory Equipment, Computer Equipment and Computer Software Received [Member]	Sep. 30, 2013 Minimum [Member] Other Lease Agreement [Member] Laboratory Equipment, Computer Software and Furniture Equipment Not Yet Received [Member]	Sep. 30, 2013 Maximum [Member] Other Lease Agreement [Member] Laboratory Equipment, Computer Equipment and Computer Software Received [Member]	Sep. 30, 2013 Maximum [Member] Other Lease Agreement [Member] Laboratory Equipment, Computer Software and Furniture Equipment Not Yet Received [Member]
Capital Leased Assets [Line Items]
Lease agreement amount	$ 1,816,000	$ 2,845,000	$ 310,000	$ 1,629,000	$ 636,000	$ 1,590,000
Lease term period							36 months	36 months	60 months	60 months
Buyout option			$ 1	$ 1	$ 1	$ 1
Interest rate							4.50%	9.00%	13.50%	23.00%