Business Segments and Geographic Information (Details Textual) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jul. 01, 2012	Jun. 30, 2013	Jul. 01, 2012	Dec. 31, 2012
Business Segment and Geographical Information (Textual) [Abstract]
Number of reportable business segment			4
Ownership percentage in Entity			50.00%
Equity in earnings of affiliates, net of income tax provision	$ 1,029,000	$ 430,000	$ 2,246,000	$ 1,178,000
SACS
Business Segment and Geographical Information (Textual) [Abstract]
Ownership percentage in Entity			50.00%
Equity in earnings of affiliates, net of income tax provision	1,300,000	1,300,000	2,500,000	2,600,000
Investment in Joint Ventures	8,300,000		8,300,000		7,800,000
Geo Amey
Business Segment and Geographical Information (Textual) [Abstract]
Equity in earnings of affiliates, net of income tax provision	200,000	900,000	300,000	1,400,000
Investment in Joint Ventures	$ (4,400,000)		$ (4,400,000)		$ (4,100,000)