Employee Benefit Plans (Tables)

6 Months Ended

Mar. 31, 2018

Retirement Benefits [Abstract]

Schedule of net benefit costs

Pension expense for the German and UK plans were as follows:

	Three Months Ended March 31,
	2017		2018
Service cost	$	267	$	243
Interest cost	82		123
Expected return on plan assets	(40)		(32)
Amortization of actuarial losses	188		79
Pension expense for defined benefit plans	$	497	$	413
	Six Months Ended March 31,
	2017		2018
Service cost	$	518	$	475
Interest cost	159		241
Expected return on plan assets	(78)		(63)
Amortization of actuarial losses	364		155
Pension expense for defined benefit plans	$	963	$	808