Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Blended tax rate		24.50%
Tax act, transition tax		$ 240,000
Operating Loss Carryforwards [Line Items]
Liability for uncertain tax positions, excluding any related interest and penalties	$ 22,000	$ 53,000
Portion of liability related to uncertain tax position which, if recognized, would impact the effective tax rate	22,000
Accrued (reversal of accrued) interest	13,000
Interest and penalties from continuing operations	800
Undistributed earnings of foreign subsidiaries	127,000
Revenue commissioners, Ireland | Subsidiaries
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	6,618,000
Foreign tax authority
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	1,724,000
Domestic tax authority
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	19,358,000
Tax credit carryforward amount subject to expiration	12,625,000
Tax credit carryforward amount not subject to expiration	6,733,000
State tax authority
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	178,000
State and local jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	33,253,000
General Business Tax Credit Carryforward | Domestic tax authority
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	$ 1,054,000