Business Segments and Geographic Information (Details Textual) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) segment	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of reportable business segments | segment			4
Equity in earnings (losses) of affiliates, net of income tax provision	$ 1,124	$ 1,174	$ 2,610	$ 2,658
SACS
Schedule of Equity Method Investments [Line Items]
Ownership percentage in Entity			50.00%
Equity in earnings (losses) of affiliates, net of income tax provision	1,100	1,200	$ 2,200	2,300
Investment in Joint Ventures	10,200		$ 10,200		$ 8,000
Geo Amey
Schedule of Equity Method Investments [Line Items]
Ownership percentage in Entity			50.00%
Equity in earnings (losses) of affiliates, net of income tax provision	100	$ 100	$ 400	$ 300
Investment in Joint Ventures	$ (1,800)		$ (1,800)		$ (2,200)