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RELATED PERSON TRANSACTIONS - Cunningham Broadcasting Corporation (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) renewal	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Related Party Transaction [Line Items]
Consolidated total debt	$ 12,539.0		$ 12,539.0
Total revenues	1,612.0	$ 1,283.0	3,123.0	$ 2,892.0
Consolidated VIEs
Related Party Transaction [Line Items]
Consolidated total debt	$ 14.0		$ 14.0		$ 16.0
Affiliated Entity \| Cunningham
Related Party Transaction [Line Items]
Agreement renewal period			8 years
Right to acquire capital stock	100.00%		100.00%
Total payments made under the LMA excluded from liabilities	$ 56.0		$ 56.0		54.0
Remaining purchase price	54.0		54.0		54.0
Purchase options, broadcast stations	$ 0.2		0.2
Proceeds from sale of master control equipment			1.0
Annual revenue from master control services			0.2
Annual revenue for share service			$ 1.0
Affiliated Entity \| Cunningham \| LMA
Related Party Transaction [Line Items]
Number of additional renewal terms \| renewal			2
Agreement renewal period			5 years
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	6.00%		6.00%
Lease payments made to entities	$ 3.0	2.0	$ 5.0	4.0
Affiliated Entity \| Cunningham \| Consolidated VIEs
Related Party Transaction [Line Items]
Consolidated total debt	7.0		7.0
Deferred financing costs	0.2		0.2
Cunningham License Related Assets \| Cunningham
Related Party Transaction [Line Items]
Total revenues	36.0	$ 32.0	72.0	$ 71.0
Guarantee Obligations
Related Party Transaction [Line Items]
Unconditional and irrevocably guaranteed debt	46.0		46.0		$ 49.0
Guarantee Obligations \| Affiliated Entity \| Cunningham
Related Party Transaction [Line Items]
Unconditional and irrevocably guaranteed debt	$ 39.0		$ 39.0