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 Extension Period

+ References

No definition available.

+ Details

Name:	rdi_LineOfCreditExtensionPeriod
Namespace Prefix:	rdi_
Data Type:	xbrli:durationItemType
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

Face (par) amount of debt instrument at time of issuance.

+ References

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+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
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

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+ Details

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

- Definition

Amount of increase (decrease) in prepaid expenses, and assets classified as other.

+ References

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+ Details

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

- Definition

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

+ References

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+ Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_FirstMortgageMember
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_VariableRateAxis=rdi_FloorRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
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Borrowings (Union Square Construction Financing) (Narrative) (Details) - USD ($)		3 Months Ended		12 Months Ended
	Aug. 08, 2019	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 29, 2020
Debt Instrument [Line Items]
(Increase) decrease in prepaid and other assets		$ 2,093,000	$ (2,544,000)
Repayment of long-term borrowings		1,540,000	$ 42,552,000
Contractual facility		250,142,000		$ 248,948,000
Emerald Creek Capital [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		55,000,000.0
Union Square Construction Financing [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		57,500,000
Contractual facility		$ 55,000,000		$ 55,000,000
Maturity date		May 06, 2024		May 06, 2024
Union Square Construction Financing [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 50,000,000.0
Interest rate					17.50%
Extension period		1 year
Union Square Construction Financing [Member] \| Mezzanine Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 7,500,000
Repayment of long-term borrowings	$ 7,500,000
Floor Rate [Member] \| Emerald Creek Capital [Member]
Debt Instrument [Line Items]
Spread over LIBOR		7.00%
London Interbank Offered Rate (LIBOR) [Member] \| Emerald Creek Capital [Member]
Debt Instrument [Line Items]
Spread over LIBOR		6.90%