Pension Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Components of net periodic pension cost (benefit)
Service cost	$ 153	$ 155	$ 459	$ 457
Interest cost	1,891	1,775	5,672	5,293
Expected return on plan assets	(3,549)	(3,234)	(10,644)	(9,634)
Amortization of actuarial loss	700	926	2,098	2,748
Administrative expenses	108	48	328	142
Net pension cost (benefit)	$ (697)	$ (330)	$ (2,087)	$ (994)