Summary of Stock Options Outstanding and Exercisable (Details) - USD ($)	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Options Outstanding Shares	201,800	159,000	89,700	89,700
Options Outstanding, Weighted Average Remaining Term	5 years 10 months 24 days
Options Outstanding Weighted Average Exercise Price	$ 17.47	$ 16.23	$ 17.27	$ 17.27
Options Outstanding Intrinsic Value	$ 513,603
Options Exercisable Shares	81,200
Option Exercisable Weighted Average Remaining Term	3 years 3 months 18 days
Options Exercisable Weighted Average Exercise Price	$ 17.18
Options Exercisable Intrinsic Value	$ 309,168
Range One
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices Minimum	$ 8.78
Range of Exercise Prices Maximum	$ 8.78
Options Outstanding Shares	34,200
Options Outstanding, Weighted Average Remaining Term	1 year 2 months 12 days
Options Outstanding Weighted Average Exercise Price	$ 8.78
Options Outstanding Intrinsic Value	$ 309,168
Options Exercisable Shares	34,200
Option Exercisable Weighted Average Remaining Term	1 year 2 months 12 days
Options Exercisable Weighted Average Exercise Price	$ 8.78
Options Exercisable Intrinsic Value	$ 309,168
Range Two
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices Minimum	$ 14.87
Range of Exercise Prices Maximum	$ 14.87
Options Outstanding Shares	69,300
Options Outstanding, Weighted Average Remaining Term	8 years 1 month 7 days
Options Outstanding Weighted Average Exercise Price	$ 14.87
Options Outstanding Intrinsic Value	$ 204,435
Range Three
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices Minimum	$ 21.42
Range of Exercise Prices Maximum	$ 26.48
Options Outstanding Shares	98,300
Options Outstanding, Weighted Average Remaining Term	6 years
Options Outstanding Weighted Average Exercise Price	$ 22.32
Options Exercisable Shares	47,000
Option Exercisable Weighted Average Remaining Term	2 years 6 months
Options Exercisable Weighted Average Exercise Price	$ 23.30