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EQUITY-BASED INCENTIVE AWARDS: (Details) - USD ($) $ / shares in Units, $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014
EQUITY-BASED INCENTIVE AWARDS |  |  |  |
Number of shares of the company's common stock permitted for issuance under the plan |  |  | 225,000 |
Number of shares awarded pursuant to the plan |  |  | 161,588 |
Number of shares that may be awarded under the plan |  |  | 63,412 |
Stock Options |  |  |  |
Omnibus incentive plan and stock option activity |  |  |  |
Granted (in shares) | 6,000 | 0 |  |
Vesting period | 5 years |  |  |
Share Based Compensation Arrangement by Share Based Payment Award Options Grants in Period Grant Date Fair Value | $ 0.1 |  |  |
Stock Option Pricing Assumptions |  |  |  |
Risk-free interest rate (as a percent) | 1.93% |  |  |
Dividend yield (as a percent) | 0.90% |  |  |
Expected volatility (as a percent) | 22.70% |  |  |
Expected life | 6 years |  |  |
Stock options issued and outstanding |  |  |  |
Number Outstanding (in shares) | 41,600 | 41,600 | 21,100 | 41,600
Weighted-Average Exercise Price (in dollars per share) | $ 33.69 | $ 33.69 | $ 64.16 | $ 33.69
Number Exercisable (in shares) |  |  | 9,100 |
Exercisable, Weighted-Average Exercise Price (in dollars per share) |  |  | $ 56.03 |
Number of Shares |  |  |  |
Outstanding at the beginning of the period (in shares) | 41,600 |  |  |
Granted (in shares) | 6,000 | 0 |  |
Exercised (in shares) | (26,500) |  |  |
Outstanding at the end of the period (in shares) | 21,100 | 41,600 |  |
Weighted Average Exercise Price |  |  |  |
Outstanding at beginning of the period (in dollars per share) | $ 33.69 |  |  |
Granted (in dollars per share) | 81.03 |  |  |
Exercised (in dollars per share) | 20.14 |  |  |
Outstanding at the end of the period (in dollars per share) | $ 64.16 | $ 33.69 |  |
Aggregate intrinsic value and fair value of options outstanding |  |  |  |
Compensation expense related to the amortization of all equity - based compensation awards | $ 0.1 | $ 0.1 |  |
Total unamortized compensation expense |  |  | $ 0.1 |
Amortization period of unamortized compensation expense | 41 months |  |  |
Aggregate intrinsic value of options outstanding |  |  | 0.3 | $ 2.1
Aggregate intrinsic value of options exercisable |  |  | $ 0.2 | $ 1.8
Total intrinsic value of options | $ 1.6 | 0.1 |  |
Total fair value of options vested | $ 0.4 | $ 0.4 |  |
Expiration period | 10 years |  |  |
Stock Options | Chief Executive Officer and Chairman |  |  |  |
Number of Shares |  |  |  |
Exercised (in shares) | (25,000) |  |  |
Weighted Average Exercise Price |  |  |  |
Exercised (in dollars per share) | $ 18.00 |  |  |
Stock Options | Fiscal 2010 |  |  |  |
Stock options issued and outstanding |  |  |  |
Number Outstanding (in shares) | 3,500 |  | 3,500 |
Remaining Weighted-Average Contractual Life | 4 years 6 months 29 days |  |  |
Weighted-Average Exercise Price (in dollars per share) | $ 51.50 |  | $ 51.50 |
Number Exercisable (in shares) |  |  | 3,500 |
Exercisable, Weighted-Average Exercise Price (in dollars per share) |  |  | $ 51.50 |
Number of Shares |  |  |  |
Outstanding at the end of the period (in shares) | 3,500 |  |  |
Weighted Average Exercise Price |  |  |  |
Outstanding at the end of the period (in dollars per share) | $ 51.50 |  |  |
Stock Options | Fiscal 2012 |  |  |  |
Stock options issued and outstanding |  |  |  |
Number Outstanding (in shares) | 4,900 |  | 4,900 |
Remaining Weighted-Average Contractual Life | 6 years 1 month 2 days |  |  |
Weighted-Average Exercise Price (in dollars per share) | $ 55.15 |  | $ 55.15 |
Number Exercisable (in shares) |  |  | 2,700 |
Exercisable, Weighted-Average Exercise Price (in dollars per share) |  |  | $ 55.04 |
Number of Shares |  |  |  |
Outstanding at the end of the period (in shares) | 4,900 |  |  |
Weighted Average Exercise Price |  |  |  |
Outstanding at the end of the period (in dollars per share) | $ 55.15 |  |  |
Stock Options | Fiscal 2012 | Minimum |  |  |  |
Stock options issued and outstanding |  |  |  |
Exercisable, Weighted-Average Exercise Price (in dollars per share) |  |  | 53.80 |
Stock Options | Fiscal 2012 | Maximum |  |  |  |
Stock options issued and outstanding |  |  |  |
Exercisable, Weighted-Average Exercise Price (in dollars per share) |  |  | $ 65.97 |
Stock Options | Fiscal 2013 |  |  |  |
Stock options issued and outstanding |  |  |  |
Number Outstanding (in shares) | 6,700 |  | 6,700 |
Remaining Weighted-Average Contractual Life | 7 years 26 days |  |  |
Weighted-Average Exercise Price (in dollars per share) | $ 62.33 |  | $ 62.33 |
Number Exercisable (in shares) |  |  | 2,900 |
Exercisable, Weighted-Average Exercise Price (in dollars per share) |  |  | $ 62.33 |
Number of Shares |  |  |  |
Outstanding at the end of the period (in shares) | 6,700 |  |  |
Weighted Average Exercise Price |  |  |  |
Outstanding at the end of the period (in dollars per share) | $ 62.33 |  |  |
Stock Options | Fiscal 2015 |  |  |  |
Stock options issued and outstanding |  |  |  |
Number Outstanding (in shares) | 6,000 |  | 6,000 |
Remaining Weighted-Average Contractual Life | 9 years 3 months 29 days |  |  |
Weighted-Average Exercise Price (in dollars per share) | $ 81.03 |  | $ 81.03 |
Number of Shares |  |  |  |
Outstanding at the end of the period (in shares) | 6,000 |  |  |
Weighted Average Exercise Price |  |  |  |
Outstanding at the end of the period (in dollars per share) | $ 81.03 |  |  |

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