Stockholders Equity - Additional Information (Details) - USD ($)					1 Months Ended					3 Months Ended	12 Months Ended
	Jan. 01, 2020	Nov. 30, 2019	Jun. 30, 2017	Apr. 30, 2017	Sep. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jan. 31, 2018	Feb. 28, 2014	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2015	May 31, 2019	Dec. 31, 2017	May 31, 2015
Class Of Stock [Line Items]
Issuance of common stock from the ATM Offering, Shares										5,733,314
Gross proceeds from issuance of common stock										$ 21,100,000
Sales commission										600,000
Other offering expenses paid										200,000
Net proceeds from issuance of common stock										$ 20,200,000
Common stock, shares authorized											200,000,000	200,000,000
Common stock, par value											$ 0.001	$ 0.001
Common stock, voting rights											Each share of common stock is entitled to one vote.
Common stock, conversion features											The shares of common stock have no preemptive or conversion rights, no redemption or sinking fund provisions, no liability for further call or assessment, and are not entitled to cumulative voting rights.
Preferred stock, shares authorized											10,000,000
Preferred stock, par value											$ 0.001
Weighted-average fair value of stock options granted											$ 0.97	$ 2.29
Accelerated vesting of stock options							46,613
Options extended exercise period							1 year
Incremental stock-based compensation expense												$ 79,400
Maximum aggregate number of common stock available purchase under employee stock purchase plan													250,000
Maximum number of shares that may be purchased by eligible participants under employee stock purchase plan													7,500
Stock issued under employee stock purchase plans											7,500	2,304
2014 Equity Incentive Plan
Class Of Stock [Line Items]
Shares reserved for issuance														200,000		940,112
Number of shares available for issuance											0			120,000
Options granted in term											10 years
2014 Equity Incentive Plan | Subsequent Event
Class Of Stock [Line Items]
Number of additional shares registered for issuance	2,323,609
Stock-based Compensation | 2011 Equity Incentive Plan
Class Of Stock [Line Items]
Percentage of increase on outstanding shares									20.00%
Stock option granted									0
Employee Stock Option
Class Of Stock [Line Items]
Stock option granted											1,270,000	802,500
Unrecognized compensation expense											$ 1,833,329
Compensation expense period expected to be recognized											2 years 3 months 21 days
Options to purchase common stock outstanding											2,904,898	2,047,237			1,517,771
Employee Stock Option | 2011 Equity Incentive Plan
Class Of Stock [Line Items]
Shares reserved for issuance																14,006
Employee Stock Option | Inducement Awards
Class Of Stock [Line Items]
Stock option granted											80,000	0
Restricted Stock Units R S U
Class Of Stock [Line Items]
Unrecognized compensation expense											$ 555,439
Compensation expense period expected to be recognized											2 years 3 months 3 days
Weighted-average fair value of RSUs granted											$ 1.93	$ 3.63
Vested and unissued RSU awards, description											Vested and unissued awards at December 31, 2018 represents RSU awards granted on August 16, 2018 for which the second vesting date was December 31, 2018, but for which issuance of awards occurred on the next business day, January 2, 2019.
Vested and unissued RSU awards granted date											Aug. 16, 2018
Vested and unissued RSU awards vesting date											Dec. 31, 2019
Vested and unissued RSU awards issuance date											Jan. 02, 2020
Restricted Stock Units R S U | Share-based Payment Arrangement, Tranche One
Class Of Stock [Line Items]
Vested and unissued RSU awards granted date											Jan. 21, 2019
Restricted Stock Units R S U | Share-based Payment Arrangement, Tranche Two
Class Of Stock [Line Items]
Vested and unissued RSU awards granted date											Sep. 12, 2019
Maximum | 2014 Equity Incentive Plan | Board Of Directors
Class Of Stock [Line Items]
Options exercise period											4 years
Minimum | 2014 Equity Incentive Plan | Board Of Directors
Class Of Stock [Line Items]
Options exercise period											1 year
Pre-funded Warrants
Class Of Stock [Line Items]
Exercise price of warrants											$ 0.01
Underwritten Public Offering
Class Of Stock [Line Items]
Common stock price per share					$ 0.65			$ 2.90
Issuance of common stock from the ATM Offering, Shares					29,298,537			13,915,000
Net proceeds from initial public offering after underwriters' discounts, commissions and offering expenses					$ 17,700,000			$ 37,700,000
Over-Allotment Option
Class Of Stock [Line Items]
Common stock price per share					$ 0.611
Issuance of common stock from the ATM Offering, Shares					3,821,548			1,815,000
Cowen ATM Offering
Class Of Stock [Line Items]
Common stock aggregate offering price						$ 40,000,000
Issuance of common stock from the ATM Offering, Shares		0									0
Deferred offering costs						$ 200,000					$ 60,000
Sales agreement termination, month and year											2019-11
Deferred offering costs written off											$ 100,000
Private Placement
Class Of Stock [Line Items]
Resale of warrants, registration statement to file, period following date of closing					30 days
Warrants to obtain effectiveness of registration statement period following closing date					90 days
Private Placement | Institutional Accredited Investors
Class Of Stock [Line Items]
Exercise price of warrants					$ 0.65						$ 0.65
Private Placement | Institutional Accredited Investors | Pre-funded Warrants
Class Of Stock [Line Items]
Issuance of warrants, shares					5,411,687						5,411,687
Number of securities called by warrants					5,411,687						5,411,687
Exercise price of warrants					$ 0.64						$ 0.64
Exercise price of warrants, exercisable subject to beneficial ownership limitations					$ 0.01						$ 0.01
Private Placement | Cantor Fitzgerald & Co. | Pre-funded Warrants
Class Of Stock [Line Items]
Agent cash fee, percentage of gross proceeds from sale of warrants					6.00%
Net proceeds from sale of warrants					$ 3,100,000
2014 Employee Stock Purchase Plan
Class Of Stock [Line Items]
Percentage of increase on outstanding shares											1.00%
Shares reserved for issuance											273,111
Vested and unissued RSU awards, description											The number of shares of common stock reserved for issuance automatically increases on January 1 of each calendar year, from January 1, 2016 to January 1, 2024 by the least of (i) 1% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, (ii) 195,000 shares, or (iii) a number determined by the Company’s board of directors that is less than (i) and (ii).
Maximum aggregate number of common stock available purchase under employee stock purchase plan											110,820
Common stock issuance offering date											Jan. 01, 2016
Common stock issuance expiration date											Jan. 01, 2024
Options to purchase common stock outstanding											195,000
Maximum contribution eligible compensation during a period to purchase common stock											15.00%
Fair market value of company common stock, shares offering price											85.00%
Fair market value of company common stock, shares purchase price											85.00%
2014 Employee Stock Purchase Plan | Subsequent Event
Class Of Stock [Line Items]
Number of additional shares registered for issuance	195,000
Employee Stock Purchase Plan
Class Of Stock [Line Items]
Net proceeds from issuance of common stock											$ 17,250	$ 9,997
Number of shares available for issuance											174,871
Common Stock
Class Of Stock [Line Items]
Issuance of common stock from the ATM Offering, Shares										300,000
Gross proceeds from issuance of common stock										$ 600,000
Stock issued under employee stock purchase plans											87,456	82,261
Sales Agreement
Class Of Stock [Line Items]
Common stock price per share				$ 0.001
Common stock aggregate offering price			$ 40,000,000	$ 20,000,000				$ 23,000,000
Cantor Sales Agreement
Class Of Stock [Line Items]
Common stock price per share		$ 0.001
Issuance of common stock from the ATM Offering, Shares											0
Deferred offering costs		$ 81,000
Reduction of commissions earned on sold shares		45,000
Cantor Sales Agreement | Maximum
Class Of Stock [Line Items]
Common stock aggregate offering price		$ 20,000,000
Percentage of commission aggregate gross proceeds from each sale of shares		3.00%