Debt Covenant, Commitment

No definition available.

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Namespace Prefix:	cmls_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Debt Covenant, Total Commitments

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Fixed Charge Coverage Ratio, Minimum

+ References

No definition available.

+ Details

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Namespace Prefix:	cmls_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Line Of Credit Facility, Debt Covenant, Outstanding Amount To Trigger Conditional Maturity Date

+ References

No definition available.

+ Details

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Namespace Prefix:	cmls_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line Of Credit Facility, Extension Option, Maximum Extension, Period Prior To Stated Maturity Date

+ References

No definition available.

+ Details

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Namespace Prefix:	cmls_
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Balance Type:	na
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.

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Data Type:	xbrli:stringItemType
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Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

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Namespace Prefix:	us-gaap_
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Balance Type:	debit
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Period Type:

- Details

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Balance Type:
Period Type:

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Debt - 2020 Revolving Credit Agreement (Details) - USD ($)		6 Months Ended
	May 02, 2024	Jun. 30, 2026	Mar. 06, 2020
Maximum \| ABL Facility
Debt Instrument [Line Items]
Debt covenant, outstanding amount to trigger conditional maturity date	$ 50,000,000.0
Minimum \| ABL Facility
Debt Instrument [Line Items]
Debt covenant, outstanding amount to trigger conditional maturity date	35,000,000.0
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 125,000,000.0		$ 100,000,000.0
Debt covenant, total commitments (as percent)			12.50%
Debt covenant, commitment			$ 10,000,000.0
Fixed charge coverage ratio (as percent)			1.0
Letters of credit outstanding		$ 60,000,000.0
Proceeds from debt		57,000,000.0
Revolving Credit Facility \| ABL Facility
Debt Instrument [Line Items]
Maximum extension, period prior to stated maturity date (in days)	90 days
Letter of Credit
Debt Instrument [Line Items]
Proceeds from debt		$ 3,000,000.0