Net Loss per Share - Additional Information (Detail) - shares		1 Months Ended				3 Months Ended	6 Months Ended
	Jul. 29, 2019	Jul. 31, 2019	Jun. 30, 2019	May 31, 2019	Mar. 31, 2019	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Restricted stock units vested shares				74,166
Common Stock [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Restricted stock units vested shares				74,166		74,166
Common Stock [Member] | Follow-on Public Offering [Member] | Subsequent Event [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Common stock, shares issued	6,325,000	6,325,000
Common Stock [Member] | Underwriter's Over-Allotment [Member] | Subsequent Event [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Common stock, shares issued	825,000	825,000
Restricted Stock Units [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Restricted stock units, vested			0	74,166
Restricted Stock Units [Member] | Executive Officers [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Anti-dilutive unvested restricted stock units outstanding			140,834			140,834	140,834
Restricted Stock Units [Member] | 2014 Equity Incentive Plan [Member] | Executive Officers [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Restricted stock units, approved and granted					215,000
Restricted Stock Units [Member] | 2014 Equity Incentive Plan [Member] | Non-employee Members of Board of Directors [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Restricted stock units, approved and granted							24,000
Employee Options [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Anti-dilutive common stock equivalents							4,705,722	3,871,194