CONDENSED CONSOLIDATING FINANCIAL STATEMENTS (Narrative) (Details) $ in Millions	Mar. 31, 2018 USD ($)
Debt Instrument [Line Items]
Long-term debt	$ 4,030.0
Sinclair Television Group, Inc.
Debt Instrument [Line Items]
Amount of debt guaranteed by parent	$ 4,008.3
Sinclair Television Group, Inc. \| 5.375% Senior Unsecured Notes due 2021
Debt Instrument [Line Items]
Interest rate	5.375%
Sinclair Television Group, Inc. \| 5.625% Senior Unsecured Notes, due 2024
Debt Instrument [Line Items]
Interest rate	5.625%
Sinclair Television Group, Inc. \| 6.125% Senior Unsecured Notes due 2022
Debt Instrument [Line Items]
Interest rate	6.125%
Sinclair Television Group, Inc. \| 5.875% Senior Unsecured Notes due 2026
Debt Instrument [Line Items]
Interest rate	5.875%
Sinclair Television Group, Inc. \| 5.125% Senior Unsecured Notes due 2027
Debt Instrument [Line Items]
Interest rate	5.125%
Sinclair Broadcast Group, Inc.
Debt Instrument [Line Items]
Amount of debt guaranteed by parent	$ 3,963.7
Sinclair Broadcast Group, Inc. \| 5.375% Senior Unsecured Notes due 2021
Debt Instrument [Line Items]
Interest rate	5.375%
Sinclair Broadcast Group, Inc. \| 5.625% Senior Unsecured Notes, due 2024
Debt Instrument [Line Items]
Interest rate	5.625%
Sinclair Broadcast Group, Inc. \| 6.125% Senior Unsecured Notes due 2022
Debt Instrument [Line Items]
Interest rate	6.125%
Sinclair Broadcast Group, Inc. \| 5.875% Senior Unsecured Notes due 2026
Debt Instrument [Line Items]
Interest rate	5.875%
Sinclair Broadcast Group, Inc. \| 5.125% Senior Unsecured Notes due 2027
Debt Instrument [Line Items]
Interest rate	5.125%

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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+ References

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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