Accounts Receivable (Allowance for Doubtful Accounts Rollforward) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period	$ 462	$ 116	$ 22
Provision adjustment - expense, net of recoveries	23	556	54
Write-offs and other adjustments - additions (deductions) to receivable balances	(449)	(210)	40
Balance at end of period	$ 36	$ 462	$ 116