Trade Accounts Receivable and Financing Receivables - Summary of Allowance for Doubtful Accounts (Details) $ in Thousands	9 Months Ended
	Jun. 30, 2020 USD ($)
Receivables [Abstract]
Balance at October 1, 2019	$ 951
Bad debt expense, net of recoveries	406
Write-offs	(168)
Balance at June 30, 2020	$ 1,189