Property, Plant And Equipment, Intangible Assets And Goodwill (Schedule Of Changes In Carrying Amount Of Goodwill) (Detail) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended
Mar. 31, 2015
Dec. 31, 2014
Goodwill [Line Items]    
Balance $ 4,187,424 $ 4,202,187
Impairment   0
Acquisitions 0 18,199
Dispositions 0 0
Foreign currency (16,792) (33,022)
Other 0 60
Balance 4,170,632 4,187,424
iHM [Member]    
Goodwill [Line Items]    
Balance 3,252,767 3,234,807
Impairment   0
Acquisitions 0 17,900
Dispositions 0 0
Foreign currency 0 0
Other 0 60
Balance 3,252,767 3,252,767
Americas Outdoor Advertising [Member]    
Goodwill [Line Items]    
Balance 584,574 585,227
Impairment   0
Acquisitions 0 0
Dispositions 0 0
Foreign currency (167) (653)
Other 0 0
Balance 584,407 584,574
International Outdoor Advertising [Member]    
Goodwill [Line Items]    
Balance 232,538 264,907
Impairment   0
Acquisitions 0 0
Dispositions 0 0
Foreign currency (16,625) (32,369)
Other 0 0
Balance 215,913 232,538
Other [Member]    
Goodwill [Line Items]    
Balance 117,545 117,246
Impairment   0
Acquisitions 0 299
Dispositions 0 0
Foreign currency 0 0
Other 0 0
Balance $ 117,545 $ 117,545