Area of a real estate property.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 970
-SubTopic 360
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-28(Column A)(Footnote 2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478979/970-360-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 970
-SubTopic 360
-Name Accounting Standards Codification
-Section 30
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478150/970-360-30-2

+ Details

Name:	us-gaap_AreaOfRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482130/360-10-45-5

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-3

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

+ Details

Name:	us-gaap_GainLossOnSaleOfProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow from the sale of formerly productive land held for sale, anything permanently fixed to it, including buildings, structures on it, and so forth.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 12
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-12

+ Details

Name:	us-gaap_ProceedsFromSaleOfPropertyHeldForSale
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

+ Details

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

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=are_A3825And3875FabianWayMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	are_PropertyTypeAxis=are_FutureDevelopmentProjectsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	are_PropertyTypeAxis=are_OperatingPropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Subsequent events (Details) $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended
Subsequent events (Details) $ in Thousands	Jul. 31, 2026 USD ($) ft²	Jun. 30, 2026 USD ($) ft²	Jun. 30, 2026 USD ($) ft²	Jun. 30, 2025 USD ($)	Jun. 30, 2026 USD ($) ft²	Jun. 30, 2025 USD ($)
Subsequent Event [Line Items]
Proceeds from sales of real estate					$ 7,350
Gain on sales of real estate			$ 0	$ 0	$ 0	$ 13,165
3825 and 3875 Fabian Way
Subsequent Event [Line Items]
Proceeds from sales of real estate		$ 163,000
Future Development Projects \| 3825 and 3875 Fabian Way
Subsequent Event [Line Items]
Area of real estate property \| ft²		250,000	250,000		250,000
Operating Properties \| 3825 and 3875 Fabian Way
Subsequent Event [Line Items]
Area of real estate property \| ft²		228,000	228,000		228,000
Subsequent Event \| 3825 and 3875 Fabian Way
Subsequent Event [Line Items]
Proceeds from sales of real estate	$ 163,000
Gain on sales of real estate	$ 0
Subsequent Event \| Future Development Projects \| 3825 and 3875 Fabian Way
Subsequent Event [Line Items]
Area of real estate property \| ft²	250,000
Subsequent Event \| Operating Properties \| 3825 and 3875 Fabian Way
Subsequent Event [Line Items]
Area of real estate property \| ft²	228,000