Intangible Assets (Tables)

12 Months Ended

Dec. 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	$	16,263	$	(5,873)	$	10,390	$	16,251	$	(4,895)	$	11,356	1-20	9
Acquired technology		52,881		(27,543)		25,338		52,809		(16,405)		36,404	1-16	4
Internally developed software		4,730		(3,522)		1,208		4,730		(2,919)		1,811	2	2
Customer relationships		99,067		(46,252)		52,815		101,933		(36,158)		65,775	1-14	6
Non-compete agreements		9,423		(7,277)		2,146		12,163		(8,558)		3,605	1-4	2
Trade names		28,110		(16,015)		12,095		28,108		(12,498)		15,610	1-8	5
Other		45,377		(27,868)		17,509		46,435		(23,530)		22,905	1-6	4
Total intangible assets	$	255,851	$	(134,350)	$	121,501	$	262,429	$	(104,963)	$	157,466	1-20	4