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Stock Option Plans - Stock Options Issued (Details) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Mar. 31, 2018 USD ($) $ / shares shares | Sep. 30, 2017 USD ($) $ / shares shares
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 1,689,000 |
Vested (in shares) | 990,375 |
Exercised (in shares) | 554,580 |
Forfeited (in shares) | 228,750 |
Exercisable at end of period (in shares) | 423,295 |
Remaining unexercised (in shares) | 905,670 |
Exercise price (in usd per share) | $ / shares | $ 41.82 |
Total value at grant date | $ | $ 11,831,465 |
Estimated forfeitures | $ | 1,759,899 |
Expensed in previous years | $ | 7,698,535 |
Expensed in 2018 | $ | 422,068 |
Future expense | $ | $ 1,950,963 |
Weighted average term of remaining future expense (in years) | 2 years 3 months 20 days |
Directors |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 322,500 |
Vested (in shares) | 322,500 |
Exercised (in shares) | 177,500 |
Forfeited (in shares) | 12,500 |
Exercisable at end of period (in shares) | 132,500 |
Remaining unexercised (in shares) | 132,500 |
Total value at grant date | $ | $ 2,149,950 |
Expensed in previous years | $ | 2,149,950 |
Expensed in 2018 | $ | 0 |
Future expense | $ | $ 0 |
Directors | 4/25/2008 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) |  | 30,000
Vested (in shares) |  | 30,000
Exercised (in shares) |  | 20,000
Forfeited (in shares) |  | 7,500
Exercisable at end of period (in shares) |  | 2,500
Remaining unexercised (in shares) |  | 2,500
Exercise price (in usd per share) | $ / shares |  | $ 50.15
Volatility (percentage) |  | 0.237
Expected life (years) |  | 7 years
Assumed yield (percentage) |  | 4.09%
Risk-free rate (percentage) |  | 3.49%
Total value at grant date | $ |  | $ 254,700
Expensed in previous years | $ |  | 254,700
Expensed in 2018 | $ |  | 0
Future expense | $ |  | $ 0
Directors | 4/24/2009 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 32,500 |
Vested (in shares) | 32,500 |
Exercised (in shares) | 27,500 |
Forfeited (in shares) | 0 |
Exercisable at end of period (in shares) | 5,000 |
Remaining unexercised (in shares) | 5,000 |
Exercise price (in usd per share) | $ / shares | $ 32.68 |
Volatility (percentage) | 0.344 |
Expected life (years) | 6 years |
Assumed yield (percentage) | 4.54% |
Risk-free rate (percentage) | 2.19% |
Total value at grant date | $ | $ 222,950 |
Expensed in previous years | $ | 222,950 |
Expensed in 2018 | $ | 0 |
Future expense | $ | $ 0 |
Directors | 5/7/2010 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 32,500 |
Vested (in shares) | 32,500 |
Exercised (in shares) | 25,000 |
Forfeited (in shares) | 2,500 |
Exercisable at end of period (in shares) | 5,000 |
Remaining unexercised (in shares) | 5,000 |
Exercise price (in usd per share) | $ / shares | $ 38.76 |
Volatility (percentage) | 0.369 |
Expected life (years) | 5 years |
Assumed yield (percentage) | 4.23% |
Risk-free rate (percentage) | 2.17% |
Total value at grant date | $ | $ 287,950 |
Expensed in previous years | $ | 287,950 |
Expensed in 2018 | $ | 0 |
Future expense | $ | $ 0 |
Directors | 5/13/2011 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 32,500 |
Vested (in shares) | 32,500 |
Exercised (in shares) | 22,500 |
Forfeited (in shares) | 2,500 |
Exercisable at end of period (in shares) | 7,500 |
Remaining unexercised (in shares) | 7,500 |
Exercise price (in usd per share) | $ / shares | $ 41.82 |
Volatility (percentage) | 0.358 |
Expected life (years) | 5 years |
Assumed yield (percentage) | 4.16% |
Risk-free rate (percentage) | 1.86% |
Total value at grant date | $ | $ 297,375 |
Expensed in previous years | $ | 297,375 |
Expensed in 2018 | $ | 0 |
Future expense | $ | $ 0 |
Directors | 5/4/2012 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 35,000 |
Vested (in shares) | 35,000 |
Exercised (in shares) | 22,500 |
Forfeited (in shares) | 0 |
Exercisable at end of period (in shares) | 12,500 |
Remaining unexercised (in shares) | 12,500 |
Exercise price (in usd per share) | $ / shares | $ 39.29 |
Volatility (percentage) | 0.348 |
Expected life (years) | 5 years |
Assumed yield (percentage) | 4.61% |
Risk-free rate (percentage) | 0.78% |
Total value at grant date | $ | $ 257,250 |
Expensed in previous years | $ | 257,250 |
Expensed in 2018 | $ | 0 |
Future expense | $ | $ 0 |
Directors | 5/10/2013 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 35,000 |
Vested (in shares) | 35,000 |
Exercised (in shares) | 22,500 |
Forfeited (in shares) | 0 |
Exercisable at end of period (in shares) | 12,500 |
Remaining unexercised (in shares) | 12,500 |
Exercise price (in usd per share) | $ / shares | $ 44.42 |
Volatility (percentage) | 0.333 |
Expected life (years) | 5 years |
Assumed yield (percentage) | 4.53% |
Risk-free rate (percentage) | 0.82% |
Total value at grant date | $ | $ 278,250 |
Expensed in previous years | $ | 278,250 |
Expensed in 2018 | $ | 0 |
Future expense | $ | $ 0 |
Directors | 5/9/2014 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 30,000 |
Vested (in shares) | 30,000 |
Exercised (in shares) | 17,500 |
Forfeited (in shares) | 0 |
Exercisable at end of period (in shares) | 12,500 |
Remaining unexercised (in shares) | 12,500 |
Exercise price (in usd per share) | $ / shares | $ 47.03 |
Volatility (percentage) | 0.173 |
Expected life (years) | 5 years |
Assumed yield (percentage) | 4.48% |
Risk-free rate (percentage) | 1.63% |
Total value at grant date | $ | $ 109,500 |
Expensed in previous years | $ | 109,500 |
Expensed in 2018 | $ | 0 |
Future expense | $ | $ 0 |
Directors | 5/8/2015 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 35,000 |
Vested (in shares) | 35,000 |
Exercised (in shares) | 12,500 |
Forfeited (in shares) | 0 |
Exercisable at end of period (in shares) | 22,500 |
Remaining unexercised (in shares) | 22,500 |
Exercise price (in usd per share) | $ / shares | $ 51.07 |
Volatility (percentage) | 0.166 |
Expected life (years) | 5 years |
Assumed yield (percentage) | 4.54% |
Risk-free rate (percentage) | 1.50% |
Total value at grant date | $ | $ 125,300 |
Expensed in previous years | $ | 125,300 |
Expensed in 2018 | $ | 0 |
Future expense | $ | $ 0 |
Directors | 5/6/2016 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 32,500 |
Vested (in shares) | 32,500 |
Exercised (in shares) | 7,500 |
Forfeited (in shares) | 0 |
Exercisable at end of period (in shares) | 25,000 |
Remaining unexercised (in shares) | 25,000 |
Exercise price (in usd per share) | $ / shares | $ 57.74 |
Volatility (percentage) | 0.166 |
Expected life (years) | 5 years |
Assumed yield (percentage) | 3.75% |
Risk-free rate (percentage) | 1.23% |
Total value at grant date | $ | $ 151,125 |
Expensed in previous years | $ | 151,125 |
Expensed in 2018 | $ | 0 |
Future expense | $ | $ 0 |
Directors | 5/5/2017 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 27,500 |
Vested (in shares) | 27,500 |
Exercised (in shares) | 0 |
Forfeited (in shares) | 0 |
Exercisable at end of period (in shares) | 27,500 |
Remaining unexercised (in shares) | 27,500 |
Exercise price (in usd per share) | $ / shares | $ 59.41 |
Volatility (percentage) | 0.173 |
Expected life (years) | 5 years |
Assumed yield (percentage) | 3.45% |
Risk-free rate (percentage) | 1.89% |
Total value at grant date | $ | $ 165,550 |
Expensed in previous years | $ | 165,550 |
Expensed in 2018 | $ | 0 |
Future expense | $ | $ 0 |
Officers |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) |  |
Vested (in shares) |  |
Exercised (in shares) |  |
Forfeited (in shares) |  |
Exercisable at end of period (in shares) |  |
Remaining unexercised (in shares) |  |
Total value at grant date | $ |  |
Estimated forfeitures | $ |  |
Expensed in previous years | $ |  |
Expensed in 2018 | $ |  |
Future expense | $ |  |
Officers | 5/13/2011 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) |  | 162,500
Vested (in shares) |  | 118,750
Exercised (in shares) |  | 103,750
Forfeited (in shares) |  | 43,750
Exercisable at end of period (in shares) |  | 15,000
Remaining unexercised (in shares) |  | 15,000
Exercise price (in usd per share) | $ / shares |  | $ 41.82
Volatility (percentage) |  | 0.330
Expected life (years) |  | 8 years
Assumed yield (percentage) |  | 4.81%
Risk-free rate (percentage) |  | 2.75%
Total value at grant date | $ |  | $ 1,366,625
Estimated forfeitures | $ |  | 367,937
Expensed in previous years | $ |  | 998,688
Expensed in 2018 | $ |  | $ 0
Future expense | $ | $ 0 |
Officers | 5/4/2012 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 242,500 |
Vested (in shares) | 107,500 |
Exercised (in shares) | 91,830 |
Forfeited (in shares) | 135,000 |
Exercisable at end of period (in shares) | 15,670 |
Remaining unexercised (in shares) | 15,670 |
Exercise price (in usd per share) | $ / shares | $ 39.29 |
Volatility (percentage) | 0.315 |
Expected life (years) | 8 years |
Assumed yield (percentage) | 5.28% |
Risk-free rate (percentage) | 1.49% |
Total value at grant date | $ | $ 1,518,050 |
Estimated forfeitures | $ | 845,100 |
Expensed in previous years | $ | 672,950 |
Expensed in 2018 | $ | 0 |
Future expense | $ | $ 0 |
Officers | 5/10/2013 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 202,500 |
Vested (in shares) | 171,875 |
Exercised (in shares) | 116,500 |
Forfeited (in shares) | 30,625 |
Exercisable at end of period (in shares) | 55,375 |
Remaining unexercised (in shares) | 55,375 |
Exercise price (in usd per share) | $ / shares | $ 44.42 |
Volatility (percentage) | 0.304 |
Expected life (years) | 8 years |
Assumed yield (percentage) | 5.12% |
Risk-free rate (percentage) | 1.49% |
Total value at grant date | $ | $ 1,401,300 |
Estimated forfeitures | $ | 211,925 |
Expensed in previous years | $ | 1,189,375 |
Expensed in 2018 | $ | 0 |
Future expense | $ | $ 0 |
Officers | 5/9/2014 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 170,000 |
Vested (in shares) | 126,875 |
Exercised (in shares) | 41,250 |
Forfeited (in shares) | 1,875 |
Exercisable at end of period (in shares) | 85,625 |
Remaining unexercised (in shares) | 126,875 |
Exercise price (in usd per share) | $ / shares | $ 47.03 |
Volatility (percentage) | 0.306 |
Expected life (years) | 7 years |
Assumed yield (percentage) | 4.89% |
Risk-free rate (percentage) | 2.17% |
Total value at grant date | $ | $ 1,349,800 |
Estimated forfeitures | $ | 14,887 |
Expensed in previous years | $ | 1,082,664 |
Expensed in 2018 | $ | 189,214 |
Future expense | $ | $ 63,035 |
Officers | 5/8/2015 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 190,000 |
Vested (in shares) | 94,375 |
Exercised (in shares) | 20,000 |
Forfeited (in shares) | 3,125 |
Exercisable at end of period (in shares) | 74,375 |
Remaining unexercised (in shares) | 166,875 |
Exercise price (in usd per share) | $ / shares | $ 51.07 |
Volatility (percentage) | 0.298 |
Expected life (years) | 7 years |
Assumed yield (percentage) | 4.94% |
Risk-free rate (percentage) | 1.89% |
Total value at grant date | $ | $ 1,584,600 |
Estimated forfeitures | $ | 141,780 |
Expensed in previous years | $ | 961,888 |
Expensed in 2018 | $ | 90,177 |
Future expense | $ | $ 390,755 |
Officers | 5/6/2016 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 194,000 |
Vested (in shares) | 48,500 |
Exercised (in shares) | 3,750 |
Forfeited (in shares) | 1,875 |
Exercisable at end of period (in shares) | 44,750 |
Remaining unexercised (in shares) | 188,375 |
Exercise price (in usd per share) | $ / shares | $ 57.74 |
Volatility (percentage) | 0.185 |
Expected life (years) | 7 years |
Assumed yield (percentage) | 3.80% |
Risk-free rate (percentage) | 1.55% |
Total value at grant date | $ | $ 1,136,840 |
Estimated forfeitures | $ | 86,628 |
Expensed in previous years | $ | 437,580 |
Expensed in 2018 | $ | 65,637 |
Future expense | $ | $ 546,995 |
Officers | 5/5/2017 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) | 205,000 |
Vested (in shares) | 0 |
Exercised (in shares) | 0 |
Forfeited (in shares) | 0 |
Exercisable at end of period (in shares) | 0 |
Remaining unexercised (in shares) | 205,000 |
Exercise price (in usd per share) | $ / shares | $ 59.41 |
Volatility (percentage) | 0.170 |
Expected life (years) | 7 years |
Assumed yield (percentage) | 3.50% |
Risk-free rate (percentage) | 2.17% |
Total value at grant date | $ | $ 1,324,300 |
Estimated forfeitures | $ | 91,642 |
Expensed in previous years | $ | 205,440 |
Expensed in 2018 | $ | 77,040 |
Future expense | $ | $ 950,178 |
Officers | 5/3/2018 |  |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |  |
Total grant (in shares) |  | 1,366,500
Vested (in shares) |  | 667,875
Exercised (in shares) |  | 377,080
Forfeited (in shares) |  | 216,250
Exercisable at end of period (in shares) |  | 290,795
Remaining unexercised (in shares) |  | 773,170
Total value at grant date | $ |  | $ 9,681,515
Estimated forfeitures | $ |  | 1,759,899
Expensed in previous years | $ |  | 5,548,585
Expensed in 2018 | $ |  | 422,068
Future expense | $ |  | $ 1,950,963

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- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5047-113901 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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