Net Loss Per Common Share - Schedule of Antidilutive Securities Excluded from Calculation of Diluted Weighted-Average Shares (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from calculation of diluted weighted-average shares outstanding		1,026,602	3,971,137	915,791
Outstanding Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from calculation of diluted weighted-average shares outstanding	1,183,322	17,255	655,026	17,255
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from calculation of diluted weighted-average shares outstanding	360,508		196,761