Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Retirement Benefits [Abstract]
Service cost	$ 217	$ 243	$ 434	$ 475
Interest cost	120	123	239	241
Expected return on plan assets	(30)	(32)	(60)	(63)
Amortization of actuarial losses	97	79	193	155
Pension expense for defined benefit plans	$ 404	$ 413	$ 806	$ 808