Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Loss Carryforwards [Line Items]
Valuation allowance net deferred tax assets	$ 5,329	$ 7,557
Liability for uncertain tax positions, excluding any related interest and penalties	22	$ 22
Liability for uncertain tax position, would impact the effective tax rate, if recognized	22
Accrued interest	14
Interest and penalties from continuing operations	1
Undistributed earnings of foreign subsidiaries	485
Revenue commissioners, Ireland | Subsidiaries
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	6,141
Foreign tax authority
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	1,724
Domestic tax authority
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	12,943
Tax credit carryforward amount subject to expiration	9,622
Tax credit carryforward amount not subject to expiration	3,321
Domestic tax authority | General Business Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	1,182
State tax authority
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	178
State and local jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	$ 25,782