Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Principles and Practices (Details Textual)

v2.4.0.6
Summary of Significant Accounting Principles and Practices (Details Textual) (USD $)
12 Months Ended
Dec. 31, 2012
Contracts
Segment
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2012
Buildings [Member]
Minimum [Member]
Dec. 31, 2012
Buildings [Member]
Maximum [Member]
Dec. 31, 2012
Machinery and Equipment [Member]
Minimum [Member]
Dec. 31, 2012
Machinery and Equipment [Member]
Maximum [Member]
Dec. 31, 2012
Test Systems Segment [Member]
Dec. 31, 2011
Test Systems Segment [Member]
Dec. 31, 2010
Test Systems Segment [Member]
Jul. 30, 2012
Max-Viz, Inc [Member]
Basis of Presentation (Textual) [Abstract]                      
Percentage of acquired stock                     100.00%
Percentage of Revenue Recognized from Long Term Fixed Price Contracts               37.00% 70.00% 95.00%  
Property, Plant and Equipment, Useful Life       25 years 40 years 4 years 10 years        
Basis of Presentation (Additional Textual) [Abstract]                      
Reportable segments 2                    
Significant contracts 0                    
Research and development, design and related engineering $ 44,900,000 $ 36,100,000 $ 28,300,000                
Options Granted 20.00%                    
Excess tax benefits from share based payment arrangements 1,252,000 1,614,000 22,000                
Depreciation expense 4,400,000 4,000,000 3,800,000                
Goodwill impairment charge 0 2,400,000 0         0 2,400,000 0  
Cash dividends $ 0