Goodwill and Other Intangible Assets (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014	Dec. 31, 2014
Intangible Assets, by category
Gross Carrying Amount	$ 204,272			$ 206,429
Accumulated Amortization	145,661			147,905
Amortization expense for intangible assets	2,137		2,553
Estimated amortization expense for next 5 years
2015	8,750	[1]
2016	8,250	[1]
2017	5,500	[1]
2018	5,250	[1]
2019	5,250	[1]
Customer related
Intangible Assets, by category
Gross Carrying Amount	154,415			157,530
Accumulated Amortization	109,674			112,211
Non-compete agreements
Intangible Assets, by category
Gross Carrying Amount	1,092			1,107
Accumulated Amortization	1,032			1,039
Patents
Intangible Assets, by category
Gross Carrying Amount	6,866			6,079
Accumulated Amortization	5,369			5,399
Technology related
Intangible Assets, by category
Gross Carrying Amount	26,009			26,548
Accumulated Amortization	21,476			21,233
Trade names
Intangible Assets, by category
Gross Carrying Amount	8,314			7,745
Accumulated Amortization	3,841			3,733
Other
Intangible Assets, by category
Gross Carrying Amount	7,576			7,420
Accumulated Amortization	$ 4,269			$ 4,290

[1] These estimated amortization expense amounts do not reflect the potential effect of future foreign currency exchange fluctuations.