Percentage of investment in related party.

No definition available.

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- Definition

The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

+ Details

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Period Type:	duration

- Definition

Term of lessor's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479773/842-30-50-3

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- Definition

Amount of operating lease income from lease payments and variable lease payments paid and payable to lessor. Includes, but is not limited to, variable lease payments not included in measurement of lease receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479773/842-30-50-5

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 270
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-Name Accounting Standards Codification
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-Paragraph 6A
-Publisher FASB
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479016/842-30-45-3

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Amount of transactions with related party during the financial reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-3

+ Details

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Balance Type:	debit
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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-SubTopic 220
-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

+ Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

Name:	us-gaap_RelatedPartyTransactionAxis=aat_ReimbursementOfOperatingExpensesMember
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RELATED PARTY TRANSACTIONS (Details) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended
	Mar. 01, 2021	Mar. 01, 2019	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Related Party Transaction [Line Items]
Rental income			$ 105,494	$ 105,468	$ 312,105	$ 301,470
General and administrative			$ 8,880	$ 8,376	26,488	23,130
American Assets, Inc. \| Related Party
Related Party Transaction [Line Items]
Term of contract	10 years	3 years
Rental income					200	200
American Assets, Inc. \| Related Party \| Office Space Lease
Related Party Transaction [Line Items]
Amounts of transaction	$ 200	$ 200
AAI Aviation, Inc. \| Related Party
Related Party Transaction [Line Items]
General and administrative					$ 100	200
WBW CHP LLC
Related Party Transaction [Line Items]
Investment in WBW CHP LLC					47.70%
WBW CHP LLC \| Reimbursement of Operating Expenses
Related Party Transaction [Line Items]
Amounts of transaction					$ 900	$ 900