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Stockholders' Equity - Additional Information (Details) - USD ($) | 12 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2016 | Oct. 01, 2015 | Sep. 30, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |
Weighted average grant date fair value of the restricted stock | $ 15.13 | $ 21.12 | $ 14.84 |  |
Stock options outstanding | 190,100 | 201,800 | 159,000 |  | 89,700
Nonqualified stock options exercised | 7,700 | 4,000 | 0 |  |
Intrinsic value of nonqualified stock options exercised | $ 41,000 | $ 45,000 |  |  |
Stock-based compensation expense | 2,300,000 | $ 5,700,000 | $ 5,200,000 |  |
Unrecognized compensation expense | $ 100,000 |  |  |  |
Expected period for recognition of unrecognized compensation expense | 9 months 18 days |  |  |  |
Restricted Stock |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |
Unrecognized compensation expense | $ 3,900,000 |  |  |  |
Expected period for recognition of unrecognized compensation expense | 2 years 7 months 6 days |  |  |  |
1997 Plan |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |
Common stock reserved for issuance | 2,250,000 |  |  |  |
Expiration date | 2017-11 |  |  |  |
Common stock available for issuance | 0 |  |  |  |
Stock options outstanding |  |  |  | 89,700 |
2014 Long Term Incentive Plan |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |
Common stock reserved for issuance | 1,500,000 |  |  |  |
Percent of outstanding common stock granted to employees | 10.00% |  |  |  |
Exercise price of stock option granted to employees | 110.00% |  |  |  |
Common stock available for issuance | 691,388 |  |  |  |
2014 Long Term Incentive Plan | Restricted Stock |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |
Shares issued | 176,450 |  |  |  |
Weighted average grant date fair value of the restricted stock | $ 15.13 |  |  |  |
Grant date fair value of restricted stock | $ 2,700,000 |  |  |  |
Restricted stock restriction period | 4 years |  |  |  |
2014 Long Term Incentive Plan | Maximum |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |
Options have a term | 10 years |  |  |  |
Outstanding shares of common stock granted to employees expiry term | 5 years |  |  |  |

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