Other Balance Sheet Information - Allowance for Expected Credit Losses Activity (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 5,162	$ 4,318
Provisions	4,858	3,020
Reversals of bad debt expense	(2,254)	(2,510)
Write-offs and adjustments	(70)	(414)
Balance at end of period	$ 7,696	$ 4,414