Stockholders' Equity - Additional Information (Details)						1 Months Ended		3 Months Ended	9 Months Ended
	Jun. 09, 2022 USD ($) $ / shares shares	Jan. 09, 2022 shares	May 25, 2021 shares	Jul. 28, 2020	Jul. 21, 2020 USD ($) $ / shares shares	Jul. 31, 2020 USD ($)	Mar. 31, 2020 shares	Sep. 30, 2022 $ / shares shares	Sep. 30, 2022 USD ($) $ / shares shares	Sep. 30, 2021 USD ($) $ / shares shares	Mar. 11, 2022 USD ($) $ / shares	Dec. 31, 2021 $ / shares shares	Mar. 26, 2020 $ / shares shares	Mar. 03, 2020 $ / shares
Class of Stock [Line Items]
Capital stock, shares authorized (in shares)								210,000,000	210,000,000
Common stock, shares authorized (in shares)								200,000,000	200,000,000			200,000,000
Common stock, par value (in USD per share) | $ / shares								$ 0.0001	$ 0.0001			$ 0.0001
Preferred stock, shares authorized (in shares)								10,000,000	10,000,000			10,000,000
Preferred stock, par value (in USD per share) | $ / shares								$ 0.0001	$ 0.0001
Reverse stock split conversion ratio			0.1
Reverse stock split, conversion ratio (in shares)			10
Common stock, shares outstanding (in shares)			15,170,678					24,462,228	24,462,228			18,815,892
Preferred stock, shares outstanding (in shares)								0	0			0
Net proceeds from the offering | $									$ 14,252,000	$ 37,600,000
Common stock issued during period (in shares)							2,108,333
Percentage of common stock sold related to warrants issued													3.00%	3.00%
Proceeds from exercise of common stock warrants | $									0	461,000
Proceeds from issuance of common stock under common stock purchase agreement | $									$ 0	$ 6,334,000
January 2018 Public Offering
Class of Stock [Line Items]
Warrants exercised during period (in shares)								0	0	150
Number of securities expired (in shares)		999,850
March 20022 Equity Distribution Agreement
Class of Stock [Line Items]
Common stock, par value (in USD per share) | $ / shares											$ 0.0001
Number of shares issued from sale (in shares)									385,025
Net proceeds from the offering | $									$ 1,334,000
Maximum value of shares of common stock authorized to be sold | $											$ 50,000,000
Average sales price per share of common stock (in usd per share) | $ / shares									$ 3.58
Oppenheimer | March 20022 Equity Distribution Agreement
Class of Stock [Line Items]
Sales commission percentage											3.00%
Oppenheimer | June 2022 Registered Direct Offering
Class of Stock [Line Items]
Placement agent fee	5.00%
Aspire Capital | July 2020 Common Stock Purchase Agreement
Class of Stock [Line Items]
Common stock issued during period (in shares)					555,555				0	493,163
Maximum value of shares of common stock authorized to be sold | $					$ 30,000,000
Common stock purchase agreement term					30 months
Closing sale price of common stock (in usd per share) | $ / shares					$ 9.00
Proceeds from issuance of common stock under common stock purchase agreement | $					$ 5,000,000					$ 6,334,000
Shares of common stock issued for commitment fee (in shares)					100,000
Value of commitment fee shares issued | $						$ 847,000
Average sales price per share of common stock (in usd per share) | $ / shares										$ 1.28
Maximum
Class of Stock [Line Items]
Reverse stock split conversion ratio				0.5
Minimum
Class of Stock [Line Items]
Reverse stock split conversion ratio				0.067
Common Warrant
Class of Stock [Line Items]
Warrant exercise price (in USD per share) | $ / shares														$ 3.00
Warrants expiration period														5 years
Warrants exercised during period (in shares)								0	0	10,000
Common Warrant | March 2020 Public Offering
Class of Stock [Line Items]
Proceeds from exercise of common stock warrants | $										$ 30,000
Common Warrant | June 2022 Registered Direct Offering
Class of Stock [Line Items]
Common stock issued during period (in shares)	2,080,696
Percentage of common stock sold related to warrants issued	4.99%
Warrant exercise price (in USD per share) | $ / shares	$ 2.851
Warrants expiration period	5 years
Restriction of additional issuance as a percentage of total issuance	0.50
Historical volatility period	100 days
Settlement amount as a percentage	1
Common Warrant | Maximum | June 2022 Registered Direct Offering
Class of Stock [Line Items]
Percentage of common stock sold related to warrants issued	9.99%
Underwriter Warrant
Class of Stock [Line Items]
Warrants issued (in shares)							59,496
Warrant exercise price (in USD per share) | $ / shares														$ 3.75
Warrants exercised during period (in shares)								0	0	48,192
Underwriter Warrant | March 2020 Public Offering
Class of Stock [Line Items]
Proceeds from exercise of common stock warrants | $										$ 181,000
Placement Agent Warrant
Class of Stock [Line Items]
Warrant exercise price (in USD per share) | $ / shares													$ 5.375
Warrants expiration period													5 years
Warrants exercised during period (in shares)								0	0	45,209
Proceeds from exercise of common stock warrants | $										$ 243,000
Placement Agent Warrant | Maximum
Class of Stock [Line Items]
Warrants issued (in shares)													55,814
Pre Funded Warrant | June 2022 Registered Direct Offering
Class of Stock [Line Items]
Common stock issued during period (in shares)	3,180,615
Percentage of common stock sold related to warrants issued	4.99%
Warrant exercise price (in USD per share) | $ / shares	$ 0.01
Pre Funded Warrant | Maximum | June 2022 Registered Direct Offering
Class of Stock [Line Items]
Percentage of common stock sold related to warrants issued	9.99%
Warrants to purchase common stock
Class of Stock [Line Items]
Weighted average exercise price per share (in USD per share) | $ / shares								$ 2.86	$ 2.86			$ 37.24
Warrants owned (in shares)								5,535,637	5,535,637			1,274,176
Warrants to purchase common stock | June 2022 Registered Direct Offering
Class of Stock [Line Items]
Net proceeds from the offering | $	$ 14,020,000
Offering costs | $	$ 948,000
Warrants to purchase common stock | Common Warrant | March 2020 Public Offering
Class of Stock [Line Items]
Warrant exercise price (in USD per share) | $ / shares								$ 3.00	$ 3.00			$ 3.00
Warrants owned (in shares)								252,417	252,417			252,417
Warrants to purchase common stock | Common Warrant | January 2018 Public Offering
Class of Stock [Line Items]
Warrant exercise price (in USD per share) | $ / shares								$ 46.60	$ 46.60			$ 46.60
Warrants owned (in shares)								0	0			999,850
Warrants to purchase common stock | Common Warrant | June 2022 Registered Direct Offering
Class of Stock [Line Items]
Warrants issued (in shares)	2,080,696
Warrant exercise price (in USD per share) | $ / shares	$ 2.851							$ 2.851	$ 2.851
Warrants owned (in shares)								5,261,311	5,261,311			0
Warrants to purchase common stock | Underwriter Warrant | March 2020 Registered Direct Offering
Class of Stock [Line Items]
Warrant exercise price (in USD per share) | $ / shares								$ 3.75	$ 3.75			$ 3.75
Warrants owned (in shares)								11,304	11,304			11,304
Warrants to purchase common stock | Placement Agent Warrant | March 2020 Registered Direct Offering
Class of Stock [Line Items]
Warrant exercise price (in USD per share) | $ / shares								$ 5.375	$ 5.375			$ 5.375
Warrants owned (in shares)								10,605	10,605			10,605
Warrants to purchase common stock | Pre Funded Warrant | June 2022 Registered Direct Offering
Class of Stock [Line Items]
Warrants issued (in shares)	3,180,615
Warrant exercise price (in USD per share) | $ / shares	$ 2.841
Warrants owned (in shares)								0	0