Defined Benefit Pension Plan (Details) - Defined benefit pension plan - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Net periodic benefit cost recognized
Interest cost	$ 166	$ 144
Expected return on plan assets	(252)	(204)
Settlement cost	(4)	0
Total net periodic benefit	$ (90)	$ (60)