Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation - Additional Information (Detail)

v2.4.0.8
Basis of Presentation - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended 9 Months Ended
Sep. 27, 2014
Sep. 28, 2013
Sep. 27, 2014
Contract
Segment
Location
Sep. 28, 2013
Schedule Of Accounting Policies [Line Items]        
Reportable segments     2  
Number of Primary locations     12  
Significant contracts with right of return     0  
Contractual life of service     24 months  
Research and development, design and related engineering $ 19.1 $ 12.4 $ 57.1 $ 38.6
Test Systems [Member]
       
Schedule Of Accounting Policies [Line Items]        
Percentage of revenue recognized from long term fixed price contracts 1.00% 62.00% 1.00% 40.00%
United States [Member]
       
Schedule Of Accounting Policies [Line Items]        
Number of Primary locations     10  
Canada [Member]
       
Schedule Of Accounting Policies [Line Items]        
Number of Primary locations     1  
France [Member]
       
Schedule Of Accounting Policies [Line Items]        
Number of Primary locations     1