Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Income Tax Contingency [Line Items]
(Reductions) additions to valuation allowance	$ 1,380	$ (500)
Operating loss carryforwards, annual utilization limits	800
Unrecognized tax benefits that would impact effective tax rate	1,700
Unrecognized tax benefits, income tax penalties and interest expense	400	400	$ 300
Unrecognized tax benefits, income tax penalties and interest accrued	$ 2,600	$ 2,600
Minimum
Income Tax Contingency [Line Items]
Number of years open for tax examinations	3 years
Maximum
Income Tax Contingency [Line Items]
Number of years open for tax examinations	5 years
Federal
Income Tax Contingency [Line Items]
Net operating loss carryforwards	$ 14,500
Foreign Tax Authority
Income Tax Contingency [Line Items]
Net operating loss carryforwards	56,400
State Jurisdiction
Income Tax Contingency [Line Items]
Net operating loss carryforwards	$ 7,200