Goodwill and Other Intangible Assets (Details 2) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Intangible Assets, by category
Gross Carrying Amount	$ 196,127		$ 195,074
Accumulated Amortization	155,658		153,507
Amortization expense for intangible assets	1,318	$ 2,105
Estimated amortization expense for next 5 years
2017	5,000
2018	4,750
2019	4,500
2020	4,250
2021	4,000
Customer related
Intangible Assets, by category
Gross Carrying Amount	147,784		146,840
Accumulated Amortization	114,386		112,610
Patents
Intangible Assets, by category
Gross Carrying Amount	5,750		5,729
Accumulated Amortization	5,606		5,534
Technology related
Intangible Assets, by category
Gross Carrying Amount	25,739		25,687
Accumulated Amortization	25,711		25,634
Trade names
Intangible Assets, by category
Gross Carrying Amount	8,308		8,306
Accumulated Amortization	4,607		4,529
Other
Intangible Assets, by category
Gross Carrying Amount	8,546		8,512
Accumulated Amortization	$ 5,348		$ 5,200