Stockholders' Equity - Additional Information (Details) - USD ($)									12 Months Ended
	Aug. 03, 2018	May 14, 2018	Apr. 09, 2018	Jan. 29, 2018	Jan. 23, 2018	Dec. 27, 2017	Dec. 14, 2017	Sep. 19, 2017	Dec. 31, 2018	Dec. 31, 2017
Stockholders Equity [Line Items]
Conversion of convertible notes payable and accrued interest to common stock, value								$ 5,674,452		$ 5,674,452
Conversion of convertible notes payable and accrued interest to common stock, shares								599,201
Stock issued during period, shares, new issues	2,555,555							1,055,961
Shares issued price per share								$ 9.47
Proceeds from issuance of common stock								$ 10,000,000
Public offering price per share	$ 18.00
Proceeds from issuance initial public offering, after deduction underwriting discounts, commissions	$ 42,700,000
Payments for Underwriting Expense	$ 3,300,000
Number of share outstanding									781,725	463,600
Awards granted under the plan									377,500
Unrecognized compensation expense									$ 5,700,000
Share based compensation arrangement by share based payment award, Average remaining vesting period									3 years 2 months 12 days
Weighted average grant date fair value of options granted									$ 12.73	$ 8.25
Series J Warrants
Stockholders Equity [Line Items]
Warants expired for aggregate share of common stock to purrchase					2,942
Series K Warrants
Stockholders Equity [Line Items]
Warants expired for aggregate share of common stock to purrchase				2,262
Series M Warrants
Stockholders Equity [Line Items]
Warants expired for aggregate share of common stock to purrchase			301,452
General and Administrative
Stockholders Equity [Line Items]
Stock based compensation expense									$ 600,000	$ 100,000
Research and Development
Stockholders Equity [Line Items]
Stock based compensation expense									$ 700,000	$ 300,000
2018 Stock Incentive Plan
Stockholders Equity [Line Items]
Number of common stock authorized for issuance		500,000
Share-based compensation arrangement by share-based payment award, description									In addition, the number of shares authorized for issuance under the 2018 Plan is automatically increased on the first day of each fiscal year beginning on January 1, 2019, and ending on (and including) January 1, 2028, in an amount equal to the lesser of (i) 4% of the outstanding shares of common stock on the last day of the immediately preceding fiscal year, or (ii) another amount (including zero) determined by the Company’s Board of Directors. Any shares subject to awards granted under the 2018 Plan that are forfeited or terminated before being exercised or settled, or are not delivered to the participant because such award is settled in cash, will again become available for issuance under the 2018 Plan. Shares withheld to satisfy the grant, exercise price or tax withholding obligation related to an award will again become available for issuance under the 2018 Plan.
Share-based compensation arrangement by share-based payment award, expiration date									Jan. 01, 2028
Share-based compensation arrangement by share-based payment award, percentage of outstanding our common stock									4.00%
Options contractual term		10 years
Available for the grant of future awards									307,072
2018 Stock Incentive Plan | Executive Officers And Employees
Stockholders Equity [Line Items]
Share-based compensation arrangement by share-based payment award, stock options vesting period		4 years
2018 Stock Incentive Plan | Executive Officers And Employees | One-year Anniversary of the Grant Date
Stockholders Equity [Line Items]
Share-based compensation arrangement by share-based payment award, Vesting percentageShare-based compensation arrangement by share-based payment award, Vesting percentage		25.00%
2018 Stock Incentive Plan | Executive Officers And Employees | Quarterly over Remaining Three Years
Stockholders Equity [Line Items]
Share-based compensation arrangement by share-based payment award, Vesting percentageShare-based compensation arrangement by share-based payment award, Vesting percentage		75.00%
2010 and 2013 Stock Incentive Plan | Maximum
Stockholders Equity [Line Items]
Number of share outstanding		635,170
2013 Stock Incentive Plan
Stockholders Equity [Line Items]
Number of common stock authorized for issuance								165,000
Options contractual term								10 years
Awards granted under the plan									0
2010 Stock Incentive Plan
Stockholders Equity [Line Items]
Number of common stock authorized for issuance								470,170
Options contractual term								10 years
Awards granted under the plan									0
Over-Allotment Option
Stockholders Equity [Line Items]
Stock issued during period, shares, new issues	333,333					130,000	916,667
Shares issued price per share						$ 12.00	$ 12.00
Proceeds from issuance of common stock						$ 1,600,000	$ 11,000,000		$ 1,100,000
Registrant
Stockholders Equity [Line Items]
Common stock held by existing shareholders								736,950
Series A Convertible Redeemable Preferred Stock
Stockholders Equity [Line Items]
Number of preferred stock converted to common stock								638,416
Series B Convertible Redeemable Preferred Stock
Stockholders Equity [Line Items]
Number of preferred stock converted to common stock								970,238