Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Summary of Intangible assets
Gross assets	$ 55,671	$ 55,671
Accumulated amortization	(33,502)	(30,903)
Intangible assets, net	22,169	24,768
Customer lists acquired
Summary of Intangible assets
Gross assets	28,123	28,123
Accumulated amortization	(19,733)	(18,368)
Intangible assets, net	8,390	9,755
Technology and patents
Summary of Intangible assets
Gross assets	24,358	24,358
Accumulated amortization	(12,645)	(11,645)
Intangible assets, net	11,713	12,713
Trade names and trademarks
Summary of Intangible assets
Gross assets	3,190	3,190
Accumulated amortization	(1,124)	(890)
Intangible assets, net	$ 2,066	$ 2,300