Employee Benefit Plans Projected Benefit Obligation and Accumulated Benefit Obligation are in Excess of Plan Assets (Details) - Pension Plan [Member] - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 47,389	$ 42,948	$ 35,541
Fair value of plan assets	27,530	25,525	$ 24,583
GERMANY
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	47,389	42,948
Accumulated benefit obligation	25,489	22,469
Fair value of plan assets	$ 27,530	$ 25,525