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Stock-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions | 1 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Apr. 30, 2016 | Feb. 29, 2016 | Sep. 30, 2015 | Feb. 28, 2015 | Feb. 28, 2014 | Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2013
2014 Equity Incentive Plan |  |  |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Common stock, capital shares reserved for future issuance |  |  |  |  | 750,000 |  |  |  |
Shares issued under the plan |  |  |  |  |  | 63,628 |  |  |
Number of shares available for grant |  |  |  |  |  | 664,911 |  |  |
2014 Non-Employee Director Equity Incentive Plan |  |  |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Common stock, capital shares reserved for future issuance |  |  |  |  | 150,000 | 101,600 |  |  |
Restricted Stock Units (RSUs) |  |  |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Unvested restricted stock outstanding |  |  | 133,506 |  |  | 159,988 | 133,506 | 106,845 | 81,555
Compensation expense |  |  |  |  |  | $ 4.2 | $ 1.9 | $ 2.1 |
Amounts not yet recognized related to non-vested stock totaled |  |  | $ 1.9 |  |  | $ 2.1 | 1.9 |  |
Weighted average remaining contractual life |  |  |  |  |  | 1 year 9 months 29 days |  |  |
Restricted Stock Units (RSUs) | 2014 Equity Incentive Plan |  |  |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Unvested restricted stock outstanding |  |  |  |  |  | 159,988 |  |  |
Restricted Stock Units (RSUs) | 2014 Equity Incentive Plan | Time Based Restricted Stock Unit |  |  |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Actual amount of RSUs earned based on cumulative earnings |  | 60.00% |  |  |  |  |  |  |
Vesting period |  | 3 years |  |  |  |  |  |  |
Restricted Stock Units (RSUs) | 2014 Equity Incentive Plan | Performance Based Restricted Stock Unit |  |  |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Vesting period |  | 3 years |  |  |  |  |  |  |
Target RSUs granted range |  | 40.00% |  |  |  |  |  |  |
Restricted Stock |  |  |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Compensation expense |  |  |  |  |  | $ 0.7 | $ 1.3 | $ 1.3 |
Weighted average remaining contractual life |  |  |  |  |  | 9 months 26 days |  |  |
Restricted Stock | 2014 Non-Employee Director Equity Incentive Plan |  |  |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Vesting period |  |  |  |  | 2 years |  |  |  |
Unvested restricted stock outstanding |  |  | 26,200 |  |  | 26,800 | 26,200 |  |
Shares issued under the plan | 1,000 | 16,000 | 1,400 | 16,000 |  |  |  |  |
Maximum number of Share granted to any individual |  |  |  |  | 12,000 |  |  |  |
Number of share issued to any individual |  |  |  |  | 4,000 |  |  |  |
Restricted stock issuable to eligible Board of Directors members annually |  |  |  |  | 2,000 |  |  |  |
Shares issued, price per share | $ 29.38 | $ 25.63 | $ 29.48 | $ 33.37 |  |  | $ 29.48 |  |
Restricted Stock | 2014 Non-Employee Director Equity Incentive Plan | Vesting of First Anniversary |  |  |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Vesting percentage |  |  |  |  | 50.00% |  |  |  |
Restricted Stock | 2014 Non-Employee Director Equity Incentive Plan | Vesting of Second Anniversary |  |  |  |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Vesting percentage |  |  |  |  | 50.00% |  |  |  |

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