PROPERTY, PLANT AND EQUIPMENT, INTANGIBLE ASSETS AND GOODWILL - Schedule Of Property, Plant And Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 4,565,781	$ 4,684,901
Less: accumulated depreciation	2,681,067	2,893,761
Property, plant and equipment, net	1,884,714	1,791,140
Land, buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	562,702	572,904
Structures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,864,442	2,835,411
Towers, transmitters and studio equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	356,664	365,991
Furniture and other equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	707,163	793,756
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	74,810	$ 116,839
International Outdoor Advertising
Property, Plant and Equipment [Line Items]
Impairment of advertising assets no longer usable	$ 2,600