Stock-Based Compensation and Warrants - Additional Information (Detail) | Aug. 23, 2019 | Aug. 22, 2019 | Mar. 28, 2019shares | May 20, 2015shares | May 14, 2015 | Sep. 30, 2019USD ($)$ / sharesshares | Aug. 31, 2019$ / sharesshares | Jul. 31, 2019$ / sharesshares | Jun. 30, 2019$ / sharesshares | Apr. 30, 2019USD ($)$ / sharesshares | Dec. 31, 2013$ / sharesshares | Sep. 30, 2019USD ($)$ / sharesshares | Sep. 30, 2019USD ($)$ / sharesshares | Jun. 30, 2019$ / sharesshares | Sep. 30, 2018USD ($) | Jun. 30, 2019$ / sharesshares | Sep. 30, 2019USD ($)IncentivePlan$ / sharesshares | Sep. 30, 2018USD ($)shares | Dec. 31, 2018shares | Jun. 30, 2014$ / sharesshares |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of equity incentive plans | IncentivePlan | | | | | | | | | | | | | | | | | 2 | | | |
Total number of options outstanding | | | | | | 691,001 | | | | | | 691,001 | 691,001 | | | | 691,001 | | 530,044 | |
Unrecognized compensation cost related to unvested stock-based compensation grants | $ | | | | | | $ 1,200,000 | | | | | | $ 1,200,000 | $ 1,200,000 | | | | $ 1,200,000 | | | |
Weighted-average remaining recognition period | | | | | | | | | | | | | | | | | 1 year 9 months 18 days | | | |
Stock-based compensation | $ | | | | | | | | | | | | | | | | | $ 1,870,000 | $ 998,000 | | |
Options granted | | | | | | | | | | | | | | | | | 186,571 | 287,577 | | |
Number of warrant to purchase common stock issued | | | | | | 4,170,651 | | | | | | 4,170,651 | 4,170,651 | | | | 4,170,651 | | | |
Warrants issued, exercise price | $ / shares | | | | | | $ 9.18 | | | | | | $ 9.18 | $ 9.18 | | | | $ 9.18 | | | |
Stock price | $ / shares | | | | | | 32.52 | | | | | | 32.52 | 32.52 | | | | $ 32.52 | | | |
Cash proceeds | $ | | | | | | | | | | | | | | | | | $ 5,269,000 | | | |
Black Scholes Merton Model [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Stock price | $ / shares | | | | | | $ 8.20 | | | | | | $ 8.20 | $ 8.20 | | | | $ 8.20 | | | |
Service Warrants [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants issued, exercise price | $ / shares | | | | | | | | | | $ 6.18 | | | | | | | | | | |
Warrant issued, shares of common stock called by warrant | | | | | | | | | | 45,154 | | | | | | | | | | |
Warrants vesting period | | | | | | | | | | 12 months | | | | | | | | | | |
Warrant, exercisable term | | | | | | | | | | 5 years | | | | | | | | | | |
Fair value of Warrants | $ | | | | | | | | | | $ 224,000 | | | | | | | | | | |
Compensation expense associated with Warrants, term | | | | | | | | | | | | | | | | 1 year | | | | |
Compensation expense associated with Warrants | $ | | | | | | | | | | | | | $ 56,000 | | | | $ 100,000 | | | |
Performance Warrants [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants issued, exercise price | $ / shares | | | | | | | | | | $ 6.18 | | | | | | | | | | |
Warrant issued, shares of common stock called by warrant | | | | | | | | | | 100,000 | | | | | | | | | | |
Warrant, exercisable term | | | | | | | | | | 5 years | | | | | | | | | | |
Fair value of Warrants | $ | | | | | | | | | | $ 497,000 | | | | | | | | | | |
Cumulative adjustment compensation expense associated with warrants | $ | | | | | | | | | | | | | $ 228,000 | | | | | | | |
Service and Performance Warrants [Member] | Black Scholes Merton Model [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Stock price | $ / shares | | | | | | | | | | $ 6.18 | | | | | | | | | | |
Service and Performance Warrants [Member] | Black Scholes Merton Model [Member] | Volatility [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants, measurement input | | | | | | | | | | 1.125 | | | | | | | | | | |
Service and Performance Warrants [Member] | Black Scholes Merton Model [Member] | Risk-Free Rate [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants, measurement input | | | | | | | | | | 0.0237 | | | | | | | | | | |
Series D Redeemable Convertible Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrant issued, shares of common stock called by warrant | | | | | | | | | | | | | | | | | | | | 63,071 |
Number of warrants expired | | | 1,759 | | | | | | | | | | | 61,312 | | | | | | |
Series D Redeemable Convertible Preferred Stock [Member] | Placement Agent [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants issued, exercise price | $ / shares | | | | | | | | | | | | | | | | | | | | $ 268.80 |
Warrant issued, shares of common stock called by warrant | | | | | | | | | | | | | | | | | | | | 1,674 |
Mahyco International [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants issued, exercise price | $ / shares | | | | | | | | | | | $ 330.40 | | | | | | | | | |
Warrant issued, shares of common stock called by warrant | | | | | | | | | | | 3,784 | | | | | | | | | |
Warrant, expiration date | | | | | | | | | | | Dec. 11, 2018 | | | | | | | | | |
Investor [Member] | Series D Redeemable Convertible Preferred Stock [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants issued, exercise price | $ / shares | | | | | | | | | | | | | | | | | | | | $ 363.20 |
Warrant issued, shares of common stock called by warrant | | | | | | | | | | | | | | | | | | | | 61,397 |
Independent Contractor [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants issued, exercise price | $ / shares | | | | | | | | $ 2.19 | | | | | | | | | | | | |
Warrant issued, shares of common stock called by warrant | | | | | | | | 10,000 | | | | | | | | | | | | |
Two Affiliated Third Parties [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants issued, exercise price | $ / shares | | | | | | | $ 1.92 | | | | | | | | | | | | | |
Warrant issued, shares of common stock called by warrant | | | | | | | 20,000 | | | | | | | | | | | | | |
2015 Employee Stock Purchase Plan [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Total number of shares reserved for issuance under plan | | | | | | 102,828 | | | | | | 102,828 | 102,828 | | | | 102,828 | | | |
Stock-based compensation | $ | | | | | | | | | | | | | $ 4,300 | | $ 4,000 | | $ 12,400 | $ 6,000 | | |
Percentage in payroll deductions to acquire shares of common stock | | | | | 15.00% | | | | | | | | | | | | | | | |
Purchase plan offering period | | | | | 6 months | | | | | | | | | | | | | | | |
Employees are able to purchase company's common stock on first trading day of offering period, percentage | | | | | 85.00% | | | | | | | | | | | | | | | |
Issuance of common stock pursuant to employee stock purchase plan | | | | | | | | | | | | | | | | | 15,389 | | | |
July 2019 Offering [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants vesting period | | | | | | | | 12 months | | | | | | | | | | | | |
Warrant, exercisable term | | | | | | | | 2 years | | | | | | | | | | | | |
Compensation expense associated with Warrants, term | | | | | | | | 2 years | | | | | | | | | | | | |
Compensation expense associated with Warrants | $ | | | | | | | | | | | | | 1,000 | | | | | | | |
August 2019 Offering [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrant, exercisable term | | | | | | | 2 years | | | | | | | | | | | | | |
Compensation expense associated with Warrants | $ | | | | | | | | | | | | | 23,000 | | | | | | | |
Warrants issuance date | | | | | | | Aug. 5, 2019 | | | | | | | | | | | | | |
Separation Agreement [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Options exercisable period | 2 years | 90 days | | | | | | | | | | | | | | | | | | |
Stock-based compensation | $ | | | | | | | | | | | | | $ 438,000 | | | | | | | |
March 2018 Purchase Agreement [Member] | Purchase Agreement [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of warrant to purchase common stock issued | | | | | | 1,297,870 | | | | | | 1,297,870 | 1,297,870 | | | | 1,297,870 | | | |
March 2018 Purchase Agreement [Member] | Purchase Agreement [Member] | Purchase Price of $10.7258 [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of warrant to purchase common stock issued | | | | | | 1,282,832 | | | | | | 1,282,832 | 1,282,832 | | | | 1,282,832 | | | |
Warrants issued, purchase price of warrants per share | $ / shares | | | | | | $ 10.7258 | | | | | | $ 10.7258 | $ 10.7258 | | | | $ 10.7258 | | | |
March 2018 Purchase Agreement [Member] | Purchase Agreement [Member] | Exercise Price of $41.5625 [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of warrant to purchase common stock issued | | | | | | 15,038 | | | | | | 15,038 | 15,038 | | | | 15,038 | | | |
Warrants issued, exercise price | $ / shares | | | | | | $ 41.5625 | | | | | | $ 41.5625 | $ 41.5625 | | | | $ 41.5625 | | | |
June 2018 Offering [Member] | Purchase Agreement [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of warrant to purchase common stock issued | | | | | | 1,461,962 | | | | | | 1,461,962 | 1,461,962 | | | | 1,461,962 | | | |
June 2018 Offering [Member] | Purchase Agreement [Member] | Purchase Price of $9.94 [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of warrant to purchase common stock issued | | | | | | 1,392,345 | | | | | | 1,392,345 | 1,392,345 | | | | 1,392,345 | | | |
Warrants issued, purchase price of warrants per share | $ / shares | | | | | | $ 9.94 | | | | | | $ 9.94 | $ 9.94 | | | | $ 9.94 | | | |
June 2018 Offering [Member] | Purchase Agreement [Member] | Exercise Price of $12.568 [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of warrant to purchase common stock issued | | | | | | 69,617 | | | | | | 69,617 | 69,617 | | | | 69,617 | | | |
Warrants issued, exercise price | $ / shares | | | | | | $ 12.568 | | | | | | $ 12.568 | $ 12.568 | | | | $ 12.568 | | | |
June 2019 Purchase Agreement [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of warrant to purchase common stock issued | | | | | | 510,309 | | | | | | 510,309 | 510,309 | | | | 510,309 | | | |
June 2019 Purchase Agreement [Member] | Placement Agent [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants issued, exercise price | $ / shares | | | | | | | | | $ 6.2938 | | | | | $ 6.2938 | | $ 6.2938 | | | | |
Warrant issued, shares of common stock called by warrant | | | | | | | | | 74,479 | | | | | 74,479 | | 74,479 | | | | |
Warrant, exercisable term | | | | | | | | | 5 years | | | | | | | | | | | |
June 2019 Purchase Agreement [Member] | Purchase Agreement [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants issued, exercise price | $ / shares | | | | | | | | | $ 5 | | | | | $ 5 | | $ 5 | | | | |
Warrant issued, shares of common stock called by warrant | | | | | | | | | 1,489,575 | | | | | 1,489,575 | | 1,489,575 | | | | |
Warrants issued, purchase price of warrants per share | $ / shares | | | | | | | | | $ 0.125 | | | | | $ 0.125 | | $ 0.125 | | | | |
Warrant, exercisable term | | | | | | | | | 5 years 6 months | | | | | | | | | | | |
Class of warrant or right, issued percentage in connection with common stock sold | | | | | | | | | 100.00% | | | | | | | | | | | |
Investors exercised warrants and purchase shares of common stock | | | | | | | | | | | | 1,053,745 | | | | | | | | |
Cash proceeds | $ | | | | | | | | | | | | $ 5,300,000 | | | | | | | | |
September 2019 Purchase Agreement [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Number of warrant to purchase common stock issued | | | | | | 725,356 | | | | | | 725,356 | 725,356 | | | | 725,356 | | | |
September 2019 Purchase Agreement [Member] | Placement Agent [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants issued, exercise price | $ / shares | | | | | | $ 9.4781 | | | | | | $ 9.4781 | $ 9.4781 | | | | $ 9.4781 | | | |
Warrant issued, shares of common stock called by warrant | | | | | | 65,942 | | | | | | 65,942 | 65,942 | | | | 65,942 | | | |
Warrant, exercisable term | | | | | | 5 years | | | | | | | | | | | | | | |
September 2019 Purchase Agreement [Member] | Purchase Agreement [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrants issued, exercise price | $ / shares | | | | | | $ 7.52 | | | | | | $ 7.52 | $ 7.52 | | | | $ 7.52 | | | |
Warrant issued, shares of common stock called by warrant | | | | | | 659,414 | | | | | | 659,414 | 659,414 | | | | 659,414 | | | |
Warrants issued, purchase price of warrants per share | $ / shares | | | | | | $ 0.125 | | | | | | $ 0.125 | $ 0.125 | | | | $ 0.125 | | | |
Warrant, exercisable term | | | | | | 5 years 6 months | | | | | | | | | | | | | | |
Class of warrant or right, issued percentage in connection with common stock sold | | | | | | 50.00% | | | | | | | | | | | | | | |
Maximum [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrant, expiration date | | | | | | | | | | | | | | | | | 2025-03 | | | |
Minimum [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Warrant, expiration date | | | | | | | | | | | | | | | | | 2023-03 | | | |
2015 Omnibus Equity Incentive Plan [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Terms under the plan | | | | | | | | | | | | | | | | | The 2015 Plan became effective in May 2015 and all shares that were reserved, but not issued, under the 2006 Plan were assumed by the 2015 Plan. Upon effectiveness, the 2015 Plan had 154,387 shares of common stock reserved for future issuance, which included 10,637 shares under the 2006 Plan that were transferred to and assumed by the 2015 Plan. The 2015 Plan provides for automatic annual increases in shares available for grant. In addition, shares subject to awards under the 2006 Plan that are forfeited or canceled will be added to the 2015 Plan. | | | |
Total number of shares reserved for issuance under plan | | | | 154,387 | | 659,490 | | | | | | 659,490 | 659,490 | | | | 659,490 | | | |
Options vesting period | | | | 4 years | | | | | | | | | | | 2 years | | | | | |
Additional shares authorized for issuance under the plan | | | | | | | | | 120,000 | | | | | | | | | | | |
Common stock available for future grant | | | | | | 29,568 | | | | | | 29,568 | 29,568 | | | | 29,568 | | | |
Total number of options outstanding | | | | | | 629,922 | | | | | | 629,922 | 629,922 | | | | 629,922 | | | |
2015 Omnibus Equity Incentive Plan [Member] | Maximum [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Options exercisable period | | | | 10 years | | | | | | | | | | | | | | | | |
2015 Omnibus Equity Incentive Plan [Member] | Share-based Compensation Award, Tranche One [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Stock options vesting percentage at end of one year | | | | 25.00% | | | | | | | | | | | | | | | | |
2006 Stock Incentive Plan [Member] | | | | | | | | | | | | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | | | | | | | | | | | | |
Total number of shares reserved for issuance under plan | | | | 10,637 | | | | | | | | | | | | | | | | |
Total number of options outstanding | | | | | | 61,079 | | | | | | 61,079 | 61,079 | | | | 61,079 | | | |