State Research and Development Credit Exchange Receivable - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounts and Other Receivables [Line Items]
Percentage of credit exchange receivable	65.00%
Estimated amounts receivable under program	$ 743,000	$ 816,000	$ 282,000