Stockholders' Equity - Additional Information (Detail) - USD ($)		3 Months Ended		9 Months Ended
	May. 11, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from issuance of common stock, net				$ 42,850,677
Contractual term of options granted				10 years
Number of Shares Exercised				0	1,991,728
Weighted Average Exercise Price Exercised				$ 0	$ 1.19
Shares withheld to meet employees' minimum statutory income tax obligation				39,665	38,768
Payments for the employees' minimum statutory income tax obligation				$ 87,770	$ 154,397
Warrant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from warrant exercised					$ 545,115
Warrants exercised					545,100
Warrants outstanding		0		0		0
Equity Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized		21,000,000		21,000,000
Maximum number of shares of stock granted to one participant				1,000,000
Minimum percentage of exercise price				100.00%
Shares available for grant under the plan		852,808		852,808
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Per share weighted average fair value of options granted				$ 1.13	$ 3.08
Proceeds from the exercise of stock options					$ 2,363,425
Recognized compensation cost related to shares of stock granted		$ 766,062	$ 643,304	$ 2,177,067	1,451,031
Unrecognized compensation cost related to nonvested outstanding stock awards		$ 3,678,779		$ 3,678,779
Weighted average period expected to be recognized				2 years 4 days
Restricted Stock [Member] | Long Term Incentive Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				3 years
Performance Stock Units [Member] | Long Term Incentive Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				3 years
Compensation costs related to awards				$ 89,911	55,463
Performance Stock Units [Member] | Long Term Incentive Program [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation award percentage				0.00%
Performance Stock Units [Member] | Long Term Incentive Program [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation award percentage				150.00%
Restricted Stock Units [Member] | Long Term Incentive Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs related to awards				$ 382,084	$ 146,866
Discretionary Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based payment discretionary awards shares granted				0	150,000
Underwritten Public Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock, shares	23,000,000
Common stock price per shares	$ 2.00
Proceeds from issuance of common stock, net	$ 42,900,000
Employees [Member] | Equity Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term of options granted				10 years
Vesting period				3 years