Stockholders' Equity (Deficit) - Additional Information (Details)									3 Months Ended			9 Months Ended		12 Months Ended
		Aug. 29, 2019	Aug. 22, 2019	Mar. 29, 2019 USD ($) $ / shares shares	Jan. 01, 2019 shares	Oct. 22, 2018 USD ($) $ / shares shares	Feb. 06, 2018 USD ($) $ / shares shares	Sep. 13, 2016 USD ($)	Sep. 30, 2019 shares	Sep. 30, 2018 USD ($) shares	Jun. 30, 2018 USD ($) shares	Sep. 30, 2019 USD ($) shares	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized									50,000,000			50,000,000		50,000,000
Common stock, shares issued									882,268			882,268		432,286
Common stock, shares outstanding									882,268			882,268		432,286
Preferred stock, shares authorized									10,000,000			10,000,000		10,000,000
Preferred stock, shares issued									0			0		0
Preferred stock, shares outstanding									0			0		0
Proceeds from issuance of common stock, net of issuance costs | $												$ 4,782,509	$ 597,743
Net proceeds from sale of common stock and warrants | $												$ 0	$ 10,728,132
Stock split												on August 22, 2019, the Company filed an amendment to its Amended and Restated Certificate of Incorporation to affect a reverse stock split of the issued and outstanding shares of common stock, at a ratio of one share for twenty shares. All share amounts and per share prices in this Quarterly Report have been adjusted to reflect the reverse stock split.
Reverse stock split ratio		0.05	0.05
Stock-based compensation, tax benefit from compensation expense | $												$ 0
Stock options, granted									0			0
Stock options, forfeited									107			143
Stock options, outstanding									9,936			9,936
Stock options, expired									499			499
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period												17,150
Share-based compensation arrangement by share-based payment award, equity instruments other than options, vested in period												0
Share-based compensation arrangement by share-based payment award, equity instruments other than options, forfeited in period												500
Share-based compensation arrangement by share-based payment award, equity instruments other than options, non-vested, outstanding									16,663			16,663
2015 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									2,710			2,710
Share-based compensation arrangement by share-based payment award, description												the number of shares that have been authorized for issuance under the 2015 Plan will be automatically increased on the first day of each fiscal year beginning on January 1, 2016 and ending on (and including) January 1, 2025, in an amount equal to the lesser of (1) 4% of the outstanding shares of common stock on the last day of the immediately preceding fiscal year, or (2) another lesser amount determined by the Company’s Board of Directors.
Share-based compensation arrangement by share-based payment award, number of shares available for grant									3,827			3,827
Share-based compensation arrangement by share-based payment award, common stock percentage												4.00%
Share-based compensation arrangement by share-based payment award, number of additional shares added					17,291
At the Market Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during period, value, new issues | $										$ 405,423	$ 192,320
At the Market Offering [Member] | Sales Agreement [Member] | Cowen and Company, LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during period, value, new issues | $								$ 11,500,000
Proceeds from issuance of common stock, net of issuance costs | $														$ 600,000
Gross proceeds from sale of common stock | $														$ 600,000
At the Market Offering [Member] | Sales Agreement [Member] | Maximum [Member] | Cowen and Company, LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate gross proceeds from issuance of common stock | $								$ 25,000,000
At the Market Offering [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during period, value, new issues | $	[1]									$ 107	$ 52
Stock issued during period, shares, new issues	[1]									10,710	5,202
At the Market Offering [Member] | Common Stock [Member] | Sales Agreement [Member] | Cowen and Company, LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during period, shares, new issues														15,912
February 2018 Public Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during period, shares, new issues							2,841,152
Shares issued, price per share | $ / shares							$ 3.25
Gross proceeds from sale of common stock and warrants | $							$ 12,000,000
Net proceeds from sale of common stock and warrants | $							$ 10,700,000
Sale of stock, description of transaction												Each unit included one twentieth of a share of common stock and one common warrant to purchase one fortieth of a share of common stock at an exercise price of $65.00 per share. Each pre-funded unit included one pre-funded warrant to purchase one twentieth of a share of common stock for an exercise price of $0.20 per share, and one common warrant to purchase one fortieth of a share of common stock at an exercise price of $65.00 per share.
Class of warrant or right, number of securities called by each warrant or right							0.025
Class of warrant or right, exercise price of warrants or rights | $ / shares							$ 65.00
Warrants exercisable period							5 years
February 2018 Public Offering [Member] | Placement Agent [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class of warrant or right, exercise price of warrants or rights | $ / shares							$ 81.25
Warrants exercisable period							5 years
February 2018 Public Offering [Member] | Common Stock [Member] | Placement Agent [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock warrants to purchase							9,231
February 2018 Public Offering [Member] | Pre-funded Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during period, shares, new issues							851,155
Shares issued, price per share | $ / shares							$ 3.24
February 2018 Public Offering [Member] | Pre-funded Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class of warrant or right, exercise price of warrants or rights | $ / shares							$ 0.20
Warrants exercised														851,155
October 2018 Public Offering [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during period, shares, new issues						111,000
Proceeds from issuance of common stock, net of issuance costs | $						$ 2,800,000
Gross proceeds from sale of common stock | $						$ 3,200,000
Shares issued, price per share | $ / shares						$ 29.00
March 2019 Public Offering [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during period, shares, new issues				450,000
Proceeds from issuance of common stock, net of issuance costs | $				$ 4,800,000
Gross proceeds from sale of common stock | $				$ 5,400,000
Shares issued, price per share | $ / shares				$ 12.00

[1] Reflects the 1-for-20 reverse stock split that became effective on August 29, 2019. Refer to Note 8 – Stockholders’ equity for further information.