| Cover Page Cover Page | Jun. 21, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Jun. 21, 2021 |
| Entity Registrant Name | SINCLAIR BROADCAST GROUP, INC. |
| Entity Incorporation, State or Country Code | MD |
| Entity File Number | 000-26076 |
| Entity Tax Identification Number | 52-1494660 |
| Entity Address, Address Line One | 10706 Beaver Dam Road |
| Entity Address, City or Town | Hunt Valley |
| Entity Address, State or Province | MD |
| Entity Address, Postal Zip Code | 21030 |
| City Area Code | 410 |
| Local Phone Number | 568-1500 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Title of 12(b) Security | Class A Common Stock, par value $ 0.01 per share |
| Trading Symbol | SBGI |
| Security Exchange Name | NASDAQ |
| Amendment Flag | false |
| Entity Central Index Key | 0000912752 |
