Pension Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Components of net periodic pension cost (benefit)
Service cost	$ 151	$ 151
Interest cost	1,880	1,759
Expected return on plan assets	(3,525)	(3,199)
Amortization of actuarial loss	692	910
Administrative expenses	110	47
Net pension cost (benefit)	$ (692)	$ (332)