Represents the annual percentage increase in aggregate purchase price of the television stations.

No definition available.

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

- Definition

Represents the amount of remaining purchase price, difference of aggregate purchase price and total payments made in pursuant to the business acquisition.

+ References

No definition available.

+ Details

Name:	sbgi_BusinessAcquisitionCostOfAcquiredEntityRemainingPurchasePrice
Namespace Prefix:	sbgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Equipment Purchase Agreement, Annual Service Consideration

+ References

No definition available.

+ Details

Name:	sbgi_EquipmentPurchaseAgreementAnnualServiceConsideration
Namespace Prefix:	sbgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Equipment Purchase Agreement, Consideration Amount

+ References

No definition available.

+ Details

Name:	sbgi_EquipmentPurchaseAgreementConsiderationAmount
Namespace Prefix:	sbgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the aggregated payments received under the LMA which are treated as a liability for the prepayment of the purchase price of the stations, and which are therefore omitted from consolidated liabilities.

+ References

No definition available.

+ Details

Name:	sbgi_LiabilitiesTreatedAsPrepaymentOfPurchasePrice
Namespace Prefix:	sbgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Purchase Options, Broadcast Stations

+ References

No definition available.

+ Details

Name:	sbgi_PurchaseOptionsBroadcastStations
Namespace Prefix:	sbgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the renewal period of agreements by related parties.

+ References

No definition available.

+ Details

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

- Definition

Represents the amount used to determine annual LMA fees required to be paid to related party.

+ References

No definition available.

+ Details

Name:	sbgi_RelatedPartyTransactionAmountUsedToDetermineAnnualLMAFeesRequiredToBePaid
Namespace Prefix:	sbgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the number of renewal periods of agreements by related parties.

+ References

No definition available.

+ Details

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

- Definition

Represents the amount paid for transactions to related party during the financial reporting period.

+ References

No definition available.

+ Details

Name:	sbgi_RelatedPartyTransactionPaymentsToRelatedParty
Namespace Prefix:	sbgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the percentage of each station's net broadcast revenue due to the related party used to determine amount of annual LMA fees required to be paid.

+ References

No definition available.

+ Details

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

- Definition

Percentage of capital stock or assets to be acquired in business combination.

+ References

No definition available.

+ Details

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

- Definition

Share Service Agreement, Annual Service Consideration

+ References

No definition available.

+ Details

Name:	sbgi_ShareServiceAgreementAnnualServiceConsideration
Namespace Prefix:	sbgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of short-term and long-term debt and lease obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13,16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

+ Details

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

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ 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 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399

+ Details

Name:	us-gaap_DeferredFinanceCostsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ 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 (b)
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14435-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14557-108349

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=118943654&loc=d3e12021-110248

+ Details

Name:	us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects the sum of all other revenue and income realized from sales and other transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party during the period.

+ References

No definition available.

+ Details

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

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(1))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

+ Details

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

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_AffiliatedEntityMember
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_RelatedPartyTransactionsByRelatedPartyAxis=sbgi_CunninghamBroadcastingCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=sbgi_CunninghamBroadcastingCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sbgi_CunninghamLicenseRelatedAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidationItemsAxis=srt_ConsolidationEliminationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

RELATED PERSON TRANSACTIONS - Cunningham Broadcasting Corporation (Details) $ in Millions	1 Months Ended		3 Months Ended								12 Months Ended
	Aug. 31, 2016 USD ($)	Apr. 30, 2016 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) renewal	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Related person transactions
Debt and lease obligations			$ 12,438.0								$ 12,438.0
Amount received													$ 20.0
Revenue			$ 1,622.0	$ 1,125.0	$ 771.0	$ 722.0	$ 894.0	$ 766.0	$ 730.0	$ 665.0	4,240.0	$ 3,055.0	2,636.0
Affiliated Entity
Related person transactions
Amount received													1.0
LMA \| Cunningham
Related person transactions
Payments to related party											$ 8.0	10.0	9.0
Cunningham \| Cunningham License Related Assets
Related person transactions
Agreement renewal period											8 years
Revenue											$ 155.0	171.0	125.0
Cunningham \| Affiliated Entity
Related person transactions
Percentage of the total capital stock held in the related party, none of which have voting rights			100.00%								100.00%
Liabilities treated as prepayment of purchase price			$ 51.0				47.0				$ 51.0	47.0
Remaining purchase price			54.0								54.0
Purchase options broadcast stations			$ 0.2								$ 0.2
Equipment purchase agreement, consideration amount		$ 1.0
Equipment purchase agreement, annual service consideration		$ 0.2
Share service agreement, annual service consideration	$ 1.0
Cunningham \| LMA \| Affiliated Entity
Related person transactions
Number of additional renewal terms \| renewal											2
Agreement renewal period											5 years
Cunningham \| Minimum \| LMA \| Affiliated Entity
Related person transactions
Percentage of net broadcast revenue used to determine annual LMA fees required to be paid			3.00%								3.00%
Amount used to determine annual LMA fees required to be paid			$ 5.0								$ 5.0
Annual increase in aggregate purchase price (as a percent)			6.00%								6.00%
Guarantee Obligations
Related person transactions
Unconditional and irrevocably guaranteed debt			$ 57.0				$ 77.0				$ 57.0	77.0
Guarantee Obligations \| Cunningham \| Affiliated Entity
Related person transactions
Unconditional and irrevocably guaranteed debt			46.0								46.0
Deferred financing costs			1.0								1.0
Consolidated VIEs \| Cunningham \| Affiliated Entity
Related person transactions
Debt and lease obligations			$ 9.0								9.0
Eliminations
Related person transactions
Revenue											$ (123.0)	$ (94.0)	$ (81.0)