Intangible Assets

3 Months Ended

Mar. 31, 2014

(5) Intangible Assets

Intangible assets other than goodwill at March 31, 2014 and December 31, 2013 were as follows:



	2014						2013
(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)	$	—
Patent costs		21,714		(6,113)		15,601		21,545		(5,960)		15,585	6 - 7	3
Acquired technology		32,498		(14,185)		18,313		30,095		(13,615)		16,480	5 - 10	5
Internally developed software		17,847		(13,223)		4,624		18,097		(12,863)		5,234	5	<1
Customer relationships		99,966		(24,089)		75,877		95,793		(18,283)		77,510	5 - 13	5
Non-compete agreements		20,445		(7,635)		12,810		16,848		(6,666)		10,182	3 - 11	3
Trade names		10,627		(2,834)		7,793		9,302		(2,211)		7,091	2 - 10	3
Other		18,637		(4,819)		13,818		11,598		(4,081)		7,517	<1 - 7	2
Intangible assets with indefinite lives:
Trademarks		2,110		—		2,110		2,110		—		2,110	N/A	N/A
Total intangible assets	$	229,719	$	(78,773)	$	150,946	$	211,263	$	(69,554)	$	141,709	<1 - 13	4

For the quarters ended March 31, 2014 and 2013, the Company capitalized $210 and $177, respectively, of costs incurred to acquire, develop and extend patents in the United States and various other countries.

Amortization expense for intangible assets for the quarters ended March 31, 2014 and 2013 was $9,204 and $3,812, respectively.

Annual amortization expense for intangible assets for 2014, 2015, 2016, 2017 and 2018 is expected to be $29,767, $23,754, $20,752, $17,799 and $13,094, respectively.