Goodwill and Other Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2017

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, 2017.

(IN MILLIONS)	Buy		Watch		Total
Balance, December 31, 2016	$	2,696	$	5,149	$	7,845
Acquisitions, divestitures and other adjustments		2		314		316
Effect of foreign currency translation		44		7		51
Balance, March 31, 2017	$	2,742	$	5,370	$	8,212

Other Intangible Assets

Other Intangible Assets

	Gross Amounts				Accumulated Amortization
	March 31,		December 31,		March 31,			December 31,
(IN MILLIONS)	2017		2016		2017			2016
Indefinite-lived intangibles:
Trade names and trademarks	$	1,921	$	1,921	$	—		$	—
Amortized intangibles:
Trade names and trademarks		147		140		(91	)		(88	)
Customer-related intangibles		3,150		3,035		(1,350	)		(1,312	)
Covenants-not-to-compete		39		39		(36	)		(36	)
Content databases(1)		168		—		(2	)		—
Computer software		2,392		2,223		(1,320	)		(1,258	)
Patents and other		172		173		(104	)		(101	)
Total	$	6,068	$	5,610	$	(2,903	)	$	(2,795	)