Intangible Assets

3 Months Ended

Mar. 31, 2015

(5) Intangible Assets

Intangible assets other than goodwill at March 31, 2015 and December 31, 2014 were as follows:



	2015						2014
(in thousands)	Gross		Accumulated Amortization		Net		Gross		Accumulated Amortization		Net		Useful Life (in years)	Weighted Average Useful Life Remaining (in years)
Intangible assets with finite lives:
Licenses	$	5,875	$	(5,875)	$	—	$	5,875	$	(5,875)	$	—	N/A	N/A
Patent costs		20,949		(7,613)		13,336		20,733		(7,369)		13,364	5-20	3
Acquired technology		71,498		(20,687)		50,811		57,383		(18,241)		39,142	3-10	4
Internally developed software		9,072		(5,878)		3,194		9,073		(5,517)		3,556	1-8	<1
Customer relationships		185,497		(39,163)		146,334		157,139		(36,975)		120,164	3-11	2
Non-compete agreements		35,114		(12,637)		22,477		35,469		(11,784)		23,685	3-11	3
Trade names		26,774		(4,684)		22,090		21,800		(4,455)		17,345	2-10	5
Other		41,983		(8,854)		33,129		39,100		(6,905)		32,195	4-10	1
Intangible assets with indefinite lives:
Trademarks		2,110		—		2,110		2,110		—		2,110	N/A	N/A
Total intangible assets	$	398,872	$	(105,391)	$	293,481	$	348,682	$	(97,121)	$	251,561	1-20	4

For the quarter ended March 31, 2015 and 2014, the Company capitalized $203 and $210, respectively, of costs incurred to internally develop and extend patents in the United States and various other countries.

Amortization expense of intangible assets for the quarter ended March 31, 2015 and 2014 was $14,517 and $9,204 respectively.

Annual amortization expense for intangible assets is expected to be $54,467, $48,813, $43,796, $35,663 and $25,876 for the years ended 2015, 2016, 2017, 2018 and 2019, respectively.