Fair Value Measurements - Additional Information (Detail) - USD ($)	1 Months Ended
	May. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Fair Value Disclosures [Line Items]
Common stock warrants liability		$ 890,105	$ 5,307,332
Warrants Fair Value Disclosure	$ 943,423
Number Of Warrants Repurchased	1,571,744