NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Nature of Operations (Details)	3 Months Ended
Mar. 31, 2021 station segment channel market
Schedule of Equity Method Investments [Line Items]
Number of reportable segments \| segment	2
Number of television stations owned \| station	186
Number of markets \| market	87
Number of channels \| channel	628

Represents the number of channels broadcasted under the agreement.

No definition available.

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- Definition

Represent the number of markets in which broadcasting and media stations are operated.

+ References

No definition available.

+ Details

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Namespace Prefix:	sbgi_
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- Definition

Represents the number of television stations owned by the entity.

+ References

No definition available.

+ Details

Name:	sbgi_NumberOfTelevisionStationsOwned
Namespace Prefix:	sbgi_
Data Type:	xbrli:integerItemType
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- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8672-108599

+ Details

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- 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

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