Pension Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Components of net periodic pension cost (benefit)
Service cost	$ 155	$ 147	$ 457	$ 457
Interest cost	1,775	2,247	5,293	6,787
Expected return on plan assets	(3,234)	(3,253)	(9,634)	(10,028)
Amortization of actuarial loss	926	489	2,748	1,401
Administrative expenses	48	45	142	131
Net pension benefit	$ (330)	$ (325)	$ (994)	$ (1,252)