Employee Benefit Plans (Schedule of Changes in Benefit Obligations and Fair Value of Plan Assets, Funded Status of the Plan, and Amount Recognized in the Financial Statements) (Details) - USD ($)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Change in fair value of plan assets:
Noncurrent liabilities	$ (6,149,527)	$ (6,912,105)
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	34,821,069	30,927,973
Change in benefit obligation:
Benefit obligation at beginning of year	35,550,987	28,850,299
Service cost	691,602	537,268
Interest cost	1,062,227	1,166,728
Actuarial loss (gain)	3,620,400	5,901,915
Benefit payments, net of retiree contributions	(927,214)	(905,223)
Benefit obligation at end of year	39,998,002	35,550,987
Change in fair value of plan assets:
Fair value of plan assets at beginning of year	33,586,671	28,184,697
Actual return on plan assets, net of taxes	4,198,174	3,907,197
Employer contributions	800,000	2,400,000
Benefit payments, net of retiree contributions	(927,214)	(905,223)
Fair value of plan assets at end of year	37,657,631	33,586,671
Funded status	(2,340,371)	(1,964,316)
Noncurrent liabilities	(2,340,371)	(1,964,316)
Net actuarial loss, net of tax	1,181,744	1,047,063
Total amounts included in other comprehensive loss, net of tax	1,181,744	1,047,063
Net actuarial loss	6,977,944	6,356,201
Amounts recognized as regulatory assets	6,977,944	6,356,201
Postretirement Plan
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	17,925,409	18,030,399
Change in benefit obligation:
Benefit obligation at beginning of year	18,030,399	16,207,322
Service cost	167,879	132,882
Interest cost	531,480	648,944
Actuarial loss (gain)	(325,269)	1,530,522
Benefit payments, net of retiree contributions	(479,080)	(489,271)
Benefit obligation at end of year	17,925,409	18,030,399
Change in fair value of plan assets:
Fair value of plan assets at beginning of year	13,082,610	12,924,957
Actual return on plan assets, net of taxes	1,112,723	346,924
Employer contributions	400,000	300,000
Benefit payments, net of retiree contributions	(479,080)	(489,271)
Fair value of plan assets at end of year	14,116,253	13,082,610
Funded status	(3,809,156)	(4,947,789)
Noncurrent liabilities	(3,809,156)	(4,947,789)
Net actuarial loss, net of tax	614,987	777,717
Total amounts included in other comprehensive loss, net of tax	614,987	777,717
Net actuarial loss	2,755,333	3,661,168
Amounts recognized as regulatory assets	$ 2,755,333	$ 3,661,168