Barter and Trade Revenues and Expenses from Continuing Operations (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Barter and trade revenues	$ 69.4	$ 66.0	$ 56.5
Barter and trade expenses	$ 68.1	$ 58.5	$ 58.8

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

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration