Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2016

Intangible Assets [Abstract]

Intangible Assets Other Than Goodwill

	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	$	16,547	$	(5,248)	$	11,299	$	16,251	$	(4,895)	$	11,356	1-19	8
Acquired technology		53,735		(19,497)		34,238		52,809		(16,405)		36,404	2-15	4
Internally developed software		4,730		(3,069)		1,661		4,730		(2,919)		1,811	3	3
Customer relationships		103,825		(39,768)		64,057		101,933		(36,158)		65,775	2-15	7
Non-compete agreements		12,043		(8,722)		3,321		12,163		(8,558)		3,605	2-5	3
Trade names		28,347		(13,456)		14,891		28,108		(12,498)		15,610	1-9	6
Other		46,455		(24,556)		21,899		46,435		(23,530)		22,905	1-7	5
Total intangible assets	$	265,682	$	(114,316)	$	151,366	$	262,429	$	(104,963)	$	157,466	1-19	5