Income Taxes (Details) - Effective income tax rate varies from the statutory federal income tax rate	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Effective income tax rate varies from the statutory federal income tax rate [Abstract]
Statutory federal income tax rate	34.00%	34.00%
Increase (decrease):
State income taxes, net of federal benefit	5.70%	5.80%
Nondeductible variable costs of shareholder usage	2.90%	4.00%
Other miscellaneous adjustments	(1.10%)	0.00%
Effective income tax rate	41.50%	43.80%