Intangible Assets

6 Months Ended

Jun. 30, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

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



	June 30, 2016						December 31, 2015
	Gross Carrying Amount		Accumulated Amortization*		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization*		Net Carrying Amount
Amortized intangible assets
Engineered Papers
Customer-related intangibles	$	10.0	$	10.0	$	—	$	10.0	$	10.0	$	—
Advanced Materials & Structures
Customer Relationships	167.7		12.2		155.5		167.7		6.4		161.3
Developed Technology	16.0		3.2		12.8		16.0		2.4		13.6
Customer Contracts	0.9		0.7		0.2		0.9		0.5		0.4
Non-Compete Agreements	1.7		0.3		1.4		1.7		0.1		1.6
Patents	1.5		0.1		1.4		1.5		0.1		1.4
Total	$	197.8	$	26.5	$	171.3	$	197.8	$	19.5	$	178.3

Unamortized intangible assets (Advanced Materials & Structures)
Trade names	$	35.6					$	35.6

* Accumulated amortization also includes adjustments for foreign currency translation.

Amortization expense of intangible assets was $3.1 million and $1.0 million for the three months ended June 30, 2016 and 2015, respectively, and $6.2 million and $2.1 million for the six months ended June 30, 2016 and 2015, respectively. Finite-lived intangibles in the AMS segment are expensed using the straight-line amortization method. The estimated average aggregate amortization expense is $11.7 million in each of the next five years.