Name:	rdi_RealEstatePropertySalePriceAdjustment
Namespace Prefix:	rdi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Area of land held.

+ References

No definition available.

+ Details

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

- Definition

Amount of depreciation expense for lessor's underlying asset for which right to use has been conveyed to lessee under operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479773/842-30-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-1

+ Details

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

- 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 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-7A

+ Details

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

- Definition

Amount of real estate investment property which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(d))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

Name:	us-gaap_RealEstateInvestmentPropertyAtCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_LandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Property And Equipment (Narrative) (Details)	1 Months Ended			3 Months Ended		6 Months Ended
Property And Equipment (Narrative) (Details)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	May 31, 2023 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) item	Jun. 30, 2024 USD ($)	May 21, 2025 USD ($)	Mar. 31, 2025 USD ($)	Jan. 31, 2025 USD ($)	May 31, 2024 a	Mar. 31, 2024 USD ($)	Feb. 23, 2024 USD ($)
Property, Plant and Equipment [Line Items]
Number of held for sale properties sold \| item						3
Depreciation expense for operating property				$ 3,400,000	$ 4,000,000.0	$ 6,700,000	$ 8,100,000
Disposal Group, Held-for-Sale, Not Discontinued Operations [Member] \| Courtenay Central ETC [Member]
Property, Plant and Equipment [Line Items]
Sale price									$ 21,500,000	$ 21,500,000
Book value	$ 14,700,000				$ 14,700,000		$ 14,700,000
Property book value adjustment	$ 0
Disposal Group, Held-for-Sale, Not Discontinued Operations [Member] \| Culver City, California [Member]
Property, Plant and Equipment [Line Items]
Sale price												$ 10,000,000.0
Adjustment to sale price			$ 0
Book value			10,800,000
Disposal Group, Held-for-Sale, Not Discontinued Operations [Member] \| Cannon Park ETC [Member]
Property, Plant and Equipment [Line Items]
Sale price				$ 20,700,000		$ 20,700,000
Area of Land \| a											9.4
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Culver City, California [Member]
Property, Plant and Equipment [Line Items]
Sale price			$ 8,300,000										$ 10,000,000.0
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Cannon Park ETC [Member]
Property, Plant and Equipment [Line Items]
Sale price								$ 20,700,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| 2483 Trenton Avenue Williamsport Pennsylvania [Member]
Property, Plant and Equipment [Line Items]
Book value		$ 460,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| 2483 Trenton Avenue Williamsport Pennsylvania [Member] \| Land [Member]
Property, Plant and Equipment [Line Items]
Property book value adjustment		$ 0