Summary of Significant Accounting Policies - Weighted Average Common Shares (Details) - shares	12 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Percentage allocated to common shares - weighted average
Weighted average shares outstanding - Basic (in shares)	12,346,025	12,499,609	12,470,664
Unvested participating shares	119,549
Total	12,465,574	12,499,609	12,470,664

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=126958026&loc=d3e1448-109256

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration