Employee Benefit Plans (Schedule of Components of Net Periodic Pension and Postretirement Benefit Cost) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 172,902	$ 134,317	$ 345,804	$ 268,634
Interest cost	265,557	291,682	531,114	583,364
Expected return on plan assets	(459,156)	(387,359)	(918,312)	(774,718)
Recognized loss	113,936	39,650	227,872	79,300
Net periodic/postretirement pension/benefit cost	93,239	78,290	186,478	156,580
Postretirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	41,970	33,221	83,940	66,442
Interest cost	132,869	162,236	265,738	324,472
Expected return on plan assets	(137,599)	(136,805)	(275,198)	(273,610)
Recognized loss	59,343	30,951	118,686	61,902
Net periodic/postretirement pension/benefit cost	$ 96,583	$ 89,603	$ 193,166	$ 179,206