No definition available.

Name:	sbgi_CommitmentsAndContingenciesLineItems
Namespace Prefix:	sbgi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

FCC National Ownership Cap, Percentage of Domestic Households Reached

+ References

No definition available.

+ Details

Name:	sbgi_FCCNationalOwnershipCapPercentageofDomesticHouseholdsReached
Namespace Prefix:	sbgi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Loss Contingency, Percentage of Domestic Households Reached, UHF Discount Applied

+ References

No definition available.

+ Details

Name:	sbgi_LossContingencyPercentageofDomesticHouseholdsReachedUHFDiscountApplied
Namespace Prefix:	sbgi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Loss Contingency, Period for Ongoing Compliance Monitoring

+ References

No definition available.

+ Details

Name:	sbgi_LossContingencyPeriodforOngoingComplianceMonitoring
Namespace Prefix:	sbgi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of separately owned television stations which have programming agreement.

+ References

No definition available.

+ Details

Name:	sbgi_NumberOfSeparatelyOwnedTelevisionStationsHavingProgrammingAgreement
Namespace Prefix:	sbgi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of stations which programs substantial portions of the broadcast day and sells advertising time during programming segments.

+ References

No definition available.

+ Details

Name:	sbgi_NumberOfStationsThatProgramsSubstantialPortionsOfBroadcastDayAndSellsAdvertisingTime
Namespace Prefix:	sbgi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- 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
Balance Type:	na
Period Type:	instant

- Definition

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14557-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349

+ Details

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

- Definition

The total number of new claims filed pertaining to a loss contingency during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349

+ Details

Name:	us-gaap_LossContingencyNewClaimsFiledNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_LitigationCaseAxis=sbgi_VariousCasesAllegingViolationOfShermanAntitrustActMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_LitigationCaseAxis=sbgi_BreachOfMergerAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_LitigationCaseAxis=sbgi_FCCConsentDecreeSettlementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	sbgi_RelatedPartyTransactionsByTypeOfServicesAxis=sbgi_LocalMarketingAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_UnfavorableRegulatoryActionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

COMMITMENTS AND CONTINGENCIES (Details) $ in Millions					9 Months Ended
COMMITMENTS AND CONTINGENCIES (Details) $ in Millions	Aug. 09, 2018 USD ($)	Aug. 07, 2018 lawsuit	Dec. 21, 2017 USD ($)	Jul. 29, 2016	Sep. 30, 2018 station	Sep. 06, 2016 station
COMMITMENTS AND CONTINGENCIES
Period subject to ongoing compliance monitoring by the FCC				36 months
FCC national ownership cap, percentage of domestic households reached						39.00%
Number of television stations owned and operated					191
Various Cases Alleging Violation Of Sherman Antitrust Act
COMMITMENTS AND CONTINGENCIES
Loss Contingency, New Claims Filed, Number \| lawsuit		22
Breach Of Merger Agreement
COMMITMENTS AND CONTINGENCIES
Proposed fine \| $	$ 1,000.0
FCC Consent Decree Settlement
COMMITMENTS AND CONTINGENCIES
Number of television stations owned and operated						34
Percentage of domestic households reached, UHF discount applied						25.00%
LMA
COMMITMENTS AND CONTINGENCIES
Number of separately owned television stations having programming agreement					2
Number of stations that programs substantial portions of broadcast day and sells advertising time					1
Unfavorable Regulatory Action
COMMITMENTS AND CONTINGENCIES
Proposed fine \| $			$ 13.4