Other Intangible Assets

12 Months Ended

Dec. 31, 2012

Other Intangible Assets

8. Other Intangible Assets

Other intangible assets at December 31 consisted of:

	2012					2011
	Gross Carrying Amount		Accumulated Amortization			Gross Carrying Amount		Accumulated Amortization
(dollars in millions)
Core technologies	$	717.7	$	(211.2	)	$	660.2	$	(161.5	)
Customer relationships		144.2		(38.8	)		144.6		(25.7	)
In-process research and development(A)		167.8		—			136.2		—
Other intangibles		216.1		(121.2	)		202.6		(105.1	)
	$	1,245.8	$	(371.2	)	$	1,143.6	$	(292.3	)

^(A) Amounts capitalized as in-process research and development are accounted for as indefinite-lived intangible assets.

Amortization expense was $82.7 million, $63.3 million and $53.1 million in 2012, 2011 and 2010, respectively. The estimated amortization expense for the years 2013 through 2017 based on the company’s amortizable intangible assets as of December 31, 2012 is as follows: 2013 - $84.7 million; 2014 - $83.7 million; 2015 - $81.1 million; 2016 - $77.6 million; and 2017 - $76.3 million.