Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2014

Goodwill and Intangible Assets Disclosure [Abstract]

Changes in Carrying Value of Goodwill

The changes in the carrying value of goodwill for our segments, IAN and CMG, for the years ended December 31,2014 and 2013 are listed below.

	IAN			CMG			Total 1
Balance as of December 31, 2012	$	3,074.6		$	506.0		$	3,580.6
Current year acquisitions	58.8			16.5			75.3
Foreign currency and other	(24.1		)	(2.8		)	(26.9		)
Balance as of December 31, 2013	$	3,109.3		$	519.7		$	3,629.0
Current year acquisitions	95.2			40.9			136.1
Foreign currency and other	(83.7		)	(12.2		)	(95.9		)
Balance as of December 31, 2014	$	3,120.8		$	548.4		$	3,669.2

1 For all periods presented we have not recorded a goodwill impairment charge.

Summary of Other Intangible Assets

The following table provides a summary of other intangible assets, which are included in other assets on our Consolidated Balance Sheets.

	December 31,
	2014							2013
	Gross Amount		Accumulated Amortization			Net Amount		Gross Amount		Accumulated Amortization			Net Amount
Customer lists	$	255.8	$	(139.3	)	$	116.5	$	228.1	$	(119.8	)	$	108.3
Trade names	71.0		(22.8		)	48.2		64.5		(19.2		)	45.3
Other	14.1		(3.8		)	10.3		14.0		(3.8		)	10.2
Total	$	340.9	$	(165.9	)	$	175.0	$	306.6	$	(142.8	)	$	163.8

Estimated future amortization of other intangible assets

The estimated annual amortization expense for other intangible assets for the next five years as of December 31, 2014 is listed below.

	2015		2016		2017		2018		2019
Estimated amortization expense	$	37.2	$	34.7	$	22.7	$	12.8	$	12.1