SUBSEQUENT EVENTS (Details) - Subsequent Event	Apr. 28, 2017 USD ($) unit	Apr. 25, 2017 USD ($)
Pacific Ridge
Subsequent Event [Line Items]
Number of units in real estate property \| unit	533
Purchase price consideration	$ 232,000,000
American Assets Trust, L.P. \| Cash Flow Hedging \| Treasury Lock \| Designated as Hedging Instrument
Subsequent Event [Line Items]
Notional Amount		$ 100,000,000
Maturity Date		May 18, 2017
Derivative fixed interest rate (in percent)		2.313%
Derivative contract term		10 years
Unsecured term loans, net \| American Assets Trust, L.P. \| Scenario, Forecast
Subsequent Event [Line Items]
Term of debt instrument		12 years

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

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- Definition

Date the derivative contract matures, in CCYY-MM-DD format.

+ References

No definition available.

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- Definition

Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

The number of units in a real estate property owned as of the balance sheet date.

+ References

No definition available.

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- Definition

The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

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- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

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