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Net Loss per Share - Additional Information (Detail) - shares		1 Months Ended			3 Months Ended		9 Months Ended
	Jun. 04, 2019	Jun. 30, 2019	May 31, 2019	Mar. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Restricted stock units, vested					0
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
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] \| Share-based Payment Arrangement, Employee [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
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] \| Director [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Restricted stock units, approved and granted	24,000						24,000
Restricted Stock Units [Member] \| 2014 Equity Incentive Plan [Member] \| Director [Member] \| Share-based Payment Arrangement, Nonemployee [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							4,575,454	3,780,390