Employee Benefit Plans (Schedule of Components of Net Periodic Pension and Postretirement Benefit Cost) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 172,902	$ 134,317	$ 518,706	$ 402,951
Interest cost	265,557	291,682	796,671	875,046
Expected return on plan assets	(459,156)	(387,359)	(1,377,468)	(1,162,077)
Recognized loss	113,936	39,650	341,808	118,950
Net periodic/postretirement pension/benefit cost	93,239	78,290	279,717	234,870
Postretirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	41,970	33,221	125,910	99,663
Interest cost	132,869	162,236	398,607	486,708
Expected return on plan assets	(137,599)	(136,805)	(412,797)	(410,415)
Recognized loss	59,343	30,951	178,029	92,853
Net periodic/postretirement pension/benefit cost	$ 96,583	$ 89,603	$ 289,749	$ 268,809