For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-42

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 275
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-URI https://asc.fasb.org//1943274/2147482861/275-10-50-20

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Reportable Segment Information - Geographic Revenue and Long-lived Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
U.S. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets, net	$ 23,525	$ 24,788
Ireland [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets, net	$ 28,707	$ 30,505
Revenue [Member] \| Geographic Concentration Risk [Member] \| Domestic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of consolidated revenue	82.00%	74.00%	79.00%
Revenue [Member] \| Geographic Concentration Risk [Member] \| Foreign [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of consolidated revenue	18.00%	26.00%	21.00%