Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation (Details)

v3.20.2
Basis of Presentation (Details)
3 Months Ended 6 Months Ended
Oct. 04, 2019
USD ($)
Jul. 12, 2019
USD ($)
Jul. 01, 2019
USD ($)
Feb. 13, 2019
USD ($)
Jun. 27, 2020
USD ($)
Sep. 28, 2019
USD ($)
Jun. 29, 2019
USD ($)
Mar. 30, 2019
USD ($)
Jun. 27, 2020
USD ($)
reporting_unit
Jun. 29, 2019
USD ($)
Dec. 31, 2019
USD ($)
Business Acquisition [Line Items]                      
Proceeds on Sale of Assets                 $ 1,600,000 $ 0  
Bad debt expense         $ 1,600,000       1,600,000    
Allowance for doubtful accounts         5,100,000       5,100,000   $ 3,600,000
Research and development, design and related engineering         22,400,000   $ 27,700,000   $ 48,600,000 54,400,000  
Number of reporting units impaired | reporting_unit                 4    
Impairment loss                 $ 86,312,000    
Right-of-use asset impairment         0   $ 0   691,000 0  
Equity Investment Other Than Temporary Impairment         3,500,000       3,493,000 $ 0  
Freedom Communication Technologies, Inc.                      
Business Acquisition [Line Items]                      
Acquisition of business, net of cash acquired     $ 21,800,000                
Cash acquired     $ 600,000                
Diagnosys                      
Business Acquisition [Line Items]                      
Cash paid to acquire stock $ 7,000,000.0                    
Fair value of contingent purchase consideration 2,500,000                    
Potential additional earn-out $ 13,000,000.0                    
Achievement period 3 years                    
Earn-out achievement benchmark $ 72,000,000.0                    
Aerospace Segment                      
Business Acquisition [Line Items]                      
Impairment loss         $ 12,600,000       $ 86,300,000    
Divestiture by Sale | Test Systems Segment                      
Business Acquisition [Line Items]                      
Total cash proceeds of divesture       $ 103,800,000              
Gain on sale, net of tax               $ 80,100,000      
Income taxes from divesture               $ 19,700,000      
Disposed by Sale | Airfield Lighting Product Line Assets                      
Business Acquisition [Line Items]                      
Proceeds on Sale of Assets   $ 1,000,000.0                  
Percentage of revenue (as a percentage)   1.00%                  
Loss on sale           $ 1,300,000