Business Acquisitions - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Arbitron	Sep. 30, 2013 Arbitron	Sep. 30, 2013 Scarborough
Disclosure Business Acquisitions Additional Information Detail [Line Items]
Business acquisition purchase price				$ 1,296
Acquisition date				Sep. 30, 2013
Percentage ownership interest acquired			100.00%	100.00%
Percentage ownership interest acquired					49.50%
Fair value of investment immediately before acquisition				75	75
Gain on investment					24
Gross contractual receivable			64	64
Acquired receivables, estimated uncollectible			4	4
Provisional allocation of purchase price to goodwill			931	931
Provisional allocation of purchase price to identified intangible assets			517	517
Acquisition related expenses			4	18
Net of cash paid for acquisitions	$ 42	$ 136