Accounts Receivable (Allowance for Doubtful Accounts Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period	$ 33	$ 325	$ 36	$ 462
Provision adjustment - expense, net of recoveries	7	0	7	4
Write-offs and other adjustments - additions (deductions) to receivable balances	(27)	(222)	(30)	(363)
Balance at end of period	$ 13	$ 103	$ 13	$ 103