Accounts Receivable (Allowance for Doubtful Accounts Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period	$ 548	$ 22
Provision adjustment - expense, net of recoveries	0	17
Write-offs and other adjustments - deductions to receivable balances	(226)	0
Balance at end of period	$ 322	$ 39