Intangible Assets

9 Months Ended

Sep. 30, 2014

Goodwill and Intangible Assets Disclosure [Abstract]

The gross carrying amount and accumulated amortization for intangible assets consisted of the following ($ in millions):



	September 30, 2014						December 31, 2013
	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount
Amortized intangible assets
Customer Relationships (Filtration)	$	45.3	$	1.6	$	43.7	$	45.3	$	0.1	$	45.2
Developed Technology (Filtration)	13.8		0.9		12.9		13.8		0.1		13.7
Total	$	59.1	$	2.5	$	56.6	$	59.1	$	0.2	$	58.9

Unamortized intangible assets (Filtration)
Trade names	$	21.8					$	21.8

Amortization expense of intangible assets was $0.8 million and $0.0 million for the three months ended September 30, 2014 and 2013, respectively, and $2.3 million and $0.2 million for the nine months ended September 30, 2014 and 2013, respectively. Finite-lived intangibles in the Filtration segment are expensed using the straight-line amortization method. The estimated aggregate amortization expense is $3.1 million in each of the next five years.