Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Sep. 30, 2023
Comprehensive Income (Loss)
Unrealized Loss for Other Postretirement Obligations	$ (255)	$ (326)
Tax Effect	54	69
Net Unrealized Loss for Other Postretirement Obligations	(201)	(257)
Unrealized Loss on Available-for-Sale Securities, net	(2,951)	(4,890)
Tax Effect	620	1,024
Net Unrealized Loss on Available-for-Sale Securities	(2,331)	(3,866)
Total Accumulated Other Comprehensive Loss	$ (2,532)	$ (4,123)