Goodwill and Other Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2013

Goodwill And Intangible Assets Disclosure [Abstract]

Summary of Changes in Carrying Amount of Goodwill

The table below summarizes the changes in the carrying amount of goodwill by reportable segment for the three months ended March 31, 2013.

(IN MILLIONS)	Buy			Watch			Expositions		Total
Balance, December 31, 2012	$	3,126		$	3,661		$	565	$	7,352
Acquisitions, divestitures and other adjustments		4			1			—		5
Effect of foreign currency translation		(34	)		(1	)		—		(35	)
Balance, March 31, 2013	$	3,096		$	3,661		$	565	$	7,322

Other Intangible Assets

Other Intangible Assets

(IN MILLIONS)	Gross Amounts				Accumulated Amortization
	March 31, 2013		December 31, 2012		March 31, 2013			December 31, 2012
Indefinite-lived intangibles:
Trade names and trademarks	$	1,921	$	1,921	$	—		$	—
Amortized intangibles:
Trade names and trademarks	$	126	$	128	$	(48	)	$	(46	)
Customer-related intangibles		2,882		2,882		(922	)		(886	)
Covenants-not-to-compete		36		36		(26	)		(25	)
Computer software		1,360		1,316		(843	)		(804	)
Patents and other		93		90		(60	)		(57	)
Total	$	4,497	$	4,452	$	(1,899	)	$	(1,818	)