Property, Plant And Equipment, Intangible Assets And Goodwill (Narrative) (Detail) $ in Millions		3 Months Ended
	Jan. 15, 2016 USD ($) Stations	Mar. 31, 2016 USD ($) Markets	Mar. 31, 2015 USD ($)
Amortization expense		$ 55.3	$ 62.9
Broadcast communication tower sites and related assets [Member]
Gain (loss) on disposal	$ 2.7
Disposal proceeds	5.5
Deferred portion of gain on asset disposal	$ 1.9
Radio stations sold | Stations	6
Non-strategic outdoor markets [Member]
Gain (loss) on disposal		281.7
Disposal proceeds		$ 596.6
Number Of Businesses sold | Markets		9
Outdoor Market Indianapolis [Member]
Disposal proceeds		$ 41.2