Restructuring Charges - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment charges		$ 2,500,000
Restructuring charges	135,607
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