Pensions and Other Post-retirement Benefits (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Components of Net Periodic Benefit Cost
Interest cost	$ 1,014	$ 975
Expected return on plan assets	(1,386)	(1,299)
Recognized net actuarial loss	461	575
Net pension expense	$ 89	$ 251