Fair Value Measurements (Rollforward of acquisition earnouts) (Details) - Fair Value, Recurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at the beginning of the period	$ 1,916	$ 5,995
Acquisitions		1,568
Payments	(1,650)	(8,111)
Reclassifications	0	0
Fair value increase	1,283	2,619
Foreign currency	(4)	(155)
Balance at the end of the period	1,545	1,916
Other Current Liabilities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at the beginning of the period	770	4,304
Acquisitions		634
Payments	(1,650)	(8,111)
Reclassifications	212	1,479
Fair value increase	1,283	2,619
Foreign currency	(4)	(155)
Balance at the end of the period	611	770
Other Noncurrent Liabilities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at the beginning of the period	1,146	1,691
Acquisitions		934
Payments	0	0
Reclassifications	(212)	(1,479)
Fair value increase	0	0
Foreign currency	0	0
Balance at the end of the period	$ 934	$ 1,146