Business Segments and Geographic Information (Details Textual) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) segment	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of reportable business segments | segment	4
Equity in earnings of affiliates, net of income tax provision	$ 1,487	$ 1,119
Investment in subsidiary	$ 0		$ 0
SACS
Schedule of Equity Method Investments [Line Items]
Ownership percentage in Entity	50.00%
Equity in earnings of affiliates, net of income tax provision	$ 1,100	$ 900
Investment in Joint Ventures	$ 10,900		11,800
Geo Amey
Schedule of Equity Method Investments [Line Items]
Ownership percentage in Entity	50.00%
Equity in earnings of affiliates, net of income tax provision	$ 300
Investment in subsidiary	$ 1,700		$ 1,300