Stock-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended				12 Months Ended			3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 2012 Plan	Dec. 31, 2012 Employee Stock Option Minimum	Dec. 31, 2012 Employee Stock Option Maximum	Dec. 31, 2012 Non-Employee Directors and Consultants	Mar. 31, 2014 Unvested Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 307,425	$ 250,071
Incentive options, vesting period					4 years	5 years	1 year	5 years
Incentive options, vesting on the first anniversary of the date of grant					20.00%	25.00%
Incentive options, term						10 years
Stock options outstanding	1,675,077	2,231,590	1,610,988
Number of shares available for future grant				944,646
Closing price of common stock	$ 12.86
Weighted average grant date fair value of share-based awards granted	$ 10.58	$ 3.26
Total fair value of stock options vested	343,667	232,617
Total unrecognized compensation cost	$ 3,364,170
Unrecognized compensation cost, weighted average remaining requisite service period	3 years 1 month 2 days
Number of unvested options	743,414