Accounts Receivable (Allowance for Doubtful Accounts Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period	$ 22	$ 36
Provision adjustment - expense, net of recoveries	17	0
Write-offs and other adjustments - deductions to receivable balances	0	(3)
Balance at end of period	$ 39	$ 33