Restructuring - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment charges	$ 2,500,000	$ 1,604,256
In-process research & development
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment charges	1,200,000
Noncash disposal of property and equipment
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment charges	300,000
Disposal of inventory
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment charges	100,000
Employee termination costs
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment charges	$ 900,000