Pension Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Components of net periodic pension cost (benefit)
Service cost	$ 160	$ 150	$ 489	$ 449
Interest cost	1,490	1,915	4,528	5,746
Expected return on plan assets	(2,904)	(3,020)	(8,796)	(9,063)
Amortization of actuarial loss	948	530	2,917	1,592
Administrative expenses	84	97	253	291
Net pension cost (benefit)	$ (222)	$ (328)	$ (609)	$ (985)