Business Segments and Geographic Information (Details Textual) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) segment	Jun. 30, 2015 USD ($)	Dec. 31, 2015 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	$ 2,131	$ 1,124	$ 3,250	$ 2,610
Investment in subsidiary	0		$ 0		$ 0
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	900	1,100	$ 1,800	2,200
Investment in Joint Ventures	10,900		$ 10,900		9,000
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	1,100	$ 100	$ 1,400	$ 400
Investment in subsidiary	$ 200		$ 200		$ (1,200)