Other Information - Barter and Trade Revenues and Expenses from Continuing Operations (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Barter and trade revenues	$ 30.0	$ 13.6
Barter and trade expenses	$ 28.1	$ 13.5

Total revenue recognized from advertising barter transactions for each income statement presented.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6406959&loc=d3e49171-111630

Name:	us-gaap_AdvertisingBarterTransactionsAdvertisingBarterRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration