Goodwill and Other Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Summary of other intangible assets
Cost	$ 32,548	$ 32,548
Accumulated Amortization	26,149	25,544
Net Book Value	6,399	7,004
Customer contracts and relationships [Member]
Summary of other intangible assets
Cost	17,381	17,381
Accumulated Amortization	12,944	12,463
Net Book Value	4,437	4,918
Patents and technology [Member]
Summary of other intangible assets
Cost	7,878	7,878
Accumulated Amortization	7,415	7,378
Net Book Value	463	500
Trademarks and trade names [Member]
Summary of other intangible assets
Cost	3,988	3,988
Accumulated Amortization	2,648	2,575
Net Book Value	1,340	1,413
Other [Member]
Summary of other intangible assets
Cost	3,301	3,301
Accumulated Amortization	3,142	3,128
Net Book Value	$ 159	$ 173