Earnings Per Share / Unit (EPS / EPU) - Additional Information (Details) - shares	Sep. 30, 2025	Sep. 30, 2024
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Unvested Restricted Stock / Unit Awards	69,105	93,952
First Industrial, L.P.
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Unvested Restricted Stock / Unit Awards	189,493	261,246

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482662/260-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
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-Section 45
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-URI https://asc.fasb.org/1943274/2147482689/260-10-45-60B

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