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, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 4,565,781	$ 4,320,502
Less: accumulated depreciation	2,681,067	2,372,340
Property, plant and equipment, net	1,884,714	1,948,162
Land, buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	562,702	570,566
Structures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,864,442	2,684,673
Towers, transmitters and studio equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	356,664	350,760
Furniture and other equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	707,163	622,848
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	74,810	$ 91,655
International Outdoor Advertising
Property, Plant and Equipment [Line Items]
Impairment of advertising assets no longer usable	$ 2,600