SHARE-BASED COMPENSATION - Non Cash Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense included in operating expenses	$ 2,612	$ 2,444	$ 5,352	$ 4,224
Income tax benefit	501	581	1,165	950
After-tax stock-based compensation expense	2,111	1,863	4,187	3,274
Station operating expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense included in operating expenses	1,044	527	2,117	1,029
Corporate general and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense included in operating expenses	$ 1,568	$ 1,917	$ 3,235	$ 3,195

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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