Restructuring - Additional information (Detail) (USD $)	0 Months Ended	12 Months Ended
	Sep. 30, 2013 Employees	Dec. 31, 2013
Laboratory transferred	26
Facilities reserve		$ 100,000
Write-down of the assets		293,000
One-Time Employee Transition Costs [Member]
Employee transition costs		101,000
Other Restructuring [Member]
Facilities reserve		$ 112,000