Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Allowance For Doubtful Accounts [Abstract]
Balance at beginning of Year	$ 17,584	$ 11,829	$ 14,812
Charged to Operations	9,478	10,948	2,914
Write-offs	(13,967)	(5,193)	(5,897)
Balance at end of year	$ 13,095	$ 17,584	$ 11,829