Income Taxes - Deferred Charges Related to Intercompany Profit Elimination (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Deferred tax asset	$ 10,043	$ 3,976
Intersegment Eliminations
Segment Reporting Information [Line Items]
Deferred tax asset	$ 2,300	$ 1,600

Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, with jurisdictional netting.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=123427490&loc=d3e31931-109318

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=123427490&loc=d3e31917-109318

Name:	us-gaap_DeferredIncomeTaxAssetsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant