Intangible Assets

9 Months Ended

Sep. 30, 2016

Intangible Assets [Abstract]

Intangible Assets

(4)  Intangible Assets

Intangible assets, net, other than goodwill, as of September 30, 2016 and December 31, 2015 were as follows:

	2016						2015
(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:
Patent costs	$	16,821	$	(5,812)	$	11,009	$	16,251	$	(4,895)	$	11,356	1-19	8
Acquired technology		53,773		(25,160)		28,613		52,809		(16,405)		36,404	2-15	4
Internally developed software		4,730		(3,371)		1,359		4,730		(2,919)		1,811	3	3
Customer relationships		102,265		(44,619)		57,646		101,933		(36,158)		65,775	2-15	7
Non-compete agreements		11,945		(9,377)		2,568		12,163		(8,558)		3,605	2-5	3
Trade names		28,435		(15,297)		13,138		28,108		(12,498)		15,610	1-9	6
Other		46,019		(26,834)		19,185		46,435		(23,530)		22,905	1-7	5
Total intangible assets	$	263,988	$	(130,470)	$	133,518	$	262,429	$	(104,963)	$	157,466	1-19	5

Amortization expense related to intangible assets was $8,857 and $26,536 for the quarter and nine months ended September 30, 2016, respectively, compared to $15,843 and $47,840 for the quarter and nine months ended September 30, 2015, respectively.

Annual amortization expense for intangible assets is expected to be $35,193,  $32,143,  $26,971,  $21,635 and $16,941 for the years ending 2016, 2017, 2018, 2019, and 2020, respectively.