Summary of secured and unsecured senior debts (Details) $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
Fixed rate debt	$ 8,511,874	$ 8,511,874
Variable-rate debt	279,992	279,992
Total Consolidated	$ 8,791,866	$ 8,791,866
Percentage of Total	100.00%	100.00%
Weighted Average Interest Rate at End of Period	3.44%	3.44%
Weighted Average Remaining Terms (in years)		12 years 1 month 6 days
Percentage of fixed rate to total debt	97.00%	97.00%
Percentage of variable-rate to total debt	3.00%	3.00%
Debt Instrument, Weighted Average Remaining Period Including Commercial Paper		11 years 10 months 24 days
Secured notes payable
Debt Instrument [Line Items]
Fixed rate debt	$ 195,196	$ 195,196
Variable-rate debt	10,002	10,002
Total Consolidated	$ 205,198	$ 205,198
Percentage of Total	2.30%	2.30%
Weighted Average Interest Rate at End of Period	3.40%	3.40%
Weighted Average Remaining Terms (in years)		2 years 2 months 12 days
Unsecured senior notes
Debt Instrument [Line Items]
Fixed rate debt	$ 8,316,678	$ 8,316,678
Variable-rate debt	0	0
Total Consolidated	$ 8,316,678	$ 8,316,678
Percentage of Total	94.60%	94.60%
Weighted Average Interest Rate at End of Period	3.54%	3.54%
Weighted Average Remaining Terms (in years)		12 years 7 months 6 days
Unsecured senior line of credit
Debt Instrument [Line Items]
Fixed rate debt	$ 0	$ 0
Variable-rate debt	0	0
Total Consolidated	$ 0	$ 0
Percentage of Total	0.00%	0.00%
Weighted Average Remaining Terms (in years)		4 years
Maturity date		Jan. 06, 2026
Unsecured senior line of credit \| LIBOR
Debt Instrument [Line Items]
Applicable margin (as a percent)		0.815%
Commercial paper program
Debt Instrument [Line Items]
Fixed rate debt	$ 0	$ 0
Variable-rate debt	269,990	269,990
Total Consolidated	$ 269,990	$ 269,990
Percentage of Total	3.10%	3.10%
Weighted Average Interest Rate at End of Period	0.29%	0.29%
Weighted Average Remaining Terms (in years)		12 days
Maturity date		Jan. 18, 2022
Weighted-average yield to maturity, commercial paper	0.24%
Commercial paper program \| Maximum
Debt Instrument [Line Items]
Number of maturity days from date of issuance		397

Represents the outstanding balance of debt as a percentage of aggregate debt outstanding.

No definition available.

Name:	are_DebtInstrumentPercentageOfOutstandingBalance
Namespace Prefix:	are_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the weighted average remaining term of the debt instrument in years.

+ References

No definition available.

+ Details

Name:	are_DebtInstrumentWeightedAverageRemainingPeriod
Namespace Prefix:	are_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Weighted Average Remaining Period Including Commercial Paper

+ References

No definition available.

+ Details

Name:	are_DebtInstrumentWeightedAverageRemainingPeriodIncludingCommercialPaper
Namespace Prefix:	are_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the outstanding balance of fixed interest rate debt as a percentage of aggregate debt outstanding.

+ References

No definition available.

+ Details

Name:	are_FixedInterestRateDebtAsPercentageOfTotalOutstandingBalance
Namespace Prefix:	are_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Long-term Debt, Percentage Bearing Fixed Interest, Amount, Net

+ References

No definition available.

+ Details

Name:	are_LongtermDebtPercentageBearingFixedInterestAmountNet
Namespace Prefix:	are_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Long-term Debt, Percentage Bearing Variable Interest, Amount, Net

+ References

No definition available.

+ Details

Name:	are_LongtermDebtPercentageBearingVariableInterestAmountNet
Namespace Prefix:	are_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of maturity days from date of issuance

+ References

No definition available.

+ Details

Name:	are_Numberofmaturitydaysfromdateofissuance
Namespace Prefix:	are_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the outstanding balance of variable interest rate debt as a percentage of aggregate debt outstanding.

+ References

No definition available.

+ Details

Name:	are_VariableInterestRateDebtAsPercentageOfTotalOutstandingBalance
Namespace Prefix:	are_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted-average yield to maturity, commercial paper

+ References

No definition available.

+ Details

Name:	are_Weightedaverageyieldtomaturitycommercialpaper
Namespace Prefix:	are_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466204&loc=SL6036836-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- 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

No definition available.

+ Details

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

- Definition

Date when the debt instrument is scheduled to be fully repaid, in YYYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=123466204&loc=SL6031897-161870

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69C
-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69B
-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: