Accounts Receivable (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Sep. 30, 2020
Receivables [Abstract]
Accounts receivable	$ 250,534	$ 264,536
Allowance for credit losses	(4,323)	(4,057)
Accounts receivable, net	246,211	$ 260,479
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at September 30, 2020	(4,057)
Charged to costs and expenses	(405)
Write-offs	179
Foreign currency and other	(40)
Balance at December 31, 2020	$ (4,323)