Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Pre-tax loss	$ (14,001,000)	$ 10,845,000	$ 6,834,000
Excludable expenses included in pre-tax loss	28,031,000	448,000
Pre-tax income	14,030,000	11,293,000
Federal research tax credit	641,000	413,000
Tax credit carryforward expiration period	20 years
Effective tax rate	(34.00%)	38.20%	40.60%
Effective tax rate excluding private placement warrants expenses	33.90%	36.70%
Accrued for interest or penalties	15,000	0
Possible decrease in unrecognized tax benefits	$ 148,000