Debt Instrument Contractual Facility Borrowing Capacity

No definition available.

Name:	rdi_DebtInstrumentContractualFacilityBorrowingCapacity
Namespace Prefix:	rdi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line Of Credit, Number Of Extension Options

+ References

No definition available.

+ Details

Name:	rdi_LineOfCreditNumberOfExtensionOptions
Namespace Prefix:	rdi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Line Of Credit, Number Of Extension Options Exercised

+ References

No definition available.

+ Details

Name:	rdi_LineOfCreditNumberOfExtensionOptionsExercised
Namespace Prefix:	rdi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Loan Tranches

+ References

No definition available.

+ Details

Name:	rdi_NumberOfLoanTranches
Namespace Prefix:	rdi_
Data Type:	xbrli:integerItemType
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 CCYY-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/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=117815213&loc=d3e19207-110258

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

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

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=rdi_TammanyMezzInvestorLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=rdi_FortyFourUnionSquareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=rdi_BankOfOzarksMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt (44 Union Square Construction Financing) (Narrative) (Details) $ in Thousands				9 Months Ended		12 Months Ended
	Jan. 24, 2020 item	Aug. 08, 2019 USD ($)	Dec. 29, 2016 USD ($) loan	Sep. 30, 2020 USD ($) item	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Contractual facility				$ 289,876		$ 283,138
Repayment of long-term borrowings				$ 28,910	$ 31,692
Tammany Mezz Investor, LLC [Member] \| Mezzanine Loan [Member]
Debt Instrument [Line Items]
Repayment of long-term borrowings		$ 7,500
44 Union Square [Member]
Debt Instrument [Line Items]
Contractual facility			$ 57,500
44 Union Square [Member] \| BankOZK [Member]
Debt Instrument [Line Items]
Number of loan tranches \| loan			3
Facility Limit			$ 50,000
Number of extension options \| item	2
Number of extension options exercised \| item				1
Maturity date				Dec. 29, 2020
44 Union Square [Member] \| Tammany Mezz Investor, LLC [Member] \| Mezzanine Loan [Member]
Debt Instrument [Line Items]
Contractual facility			$ 7,500