Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Principles and Practices - Narrative (Details)

v3.20.4
Summary of Significant Accounting Principles and Practices - Narrative (Details)
 3 Months Ended 12 Months Ended
Feb. 13, 2021
USD ($)
Oct. 04, 2019
USD ($)
Jul. 12, 2019
USD ($)
Jul. 01, 2019
USD ($)
Feb. 13, 2019
USD ($)
Dec. 31, 2020
reporting_unit
Mar. 28, 2020
reporting_unit
Mar. 30, 2019
USD ($)
Dec. 31, 2020
USD ($)
reporting_unit
segment
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Number of reportable segments | segment                 2    
Business acquisition purchase price paid in cash                 $ 0 $ 28,907,000 $ 0
COVID-19 related government assistance amount                 2,700,000    
Research and development, design and related engineering                 $ 86,800,000 108,900,000 114,300,000
Cash and cash equivalents maturity period (in months)                 3 months    
Depreciation expense                 $ 13,300,000 13,700,000 15,000,000.0
Impairment charge to right-of-use                 $ 691,000 1,019,000  
Long-lived asset impairment charge                   9,500,000  
Number of reporting units | reporting_unit             8        
Number of reporting units impaired | reporting_unit                 4    
Impairment charge                 $ 86,312,000 1,610,000 0
Number of reporting units have goodwill and subject to goodwill impairment test | reporting_unit           5     5    
Intangible asset impairment charge                 $ 0   0
Equity investment impairment                 3,493,000 5,000,000 0
Cumulative pretax loss position period           3 years          
Cash dividends paid                 0 0 $ 0
Cost of Products Sold                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
COVID-19 related government assistance amount                 2,400,000    
Selling, General and Administrative Expenses                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
COVID-19 related government assistance amount                 $ 300,000    
Astronics AeroSat Corporation                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Impairment charge                   1,600,000  
Disposed of by Sale | Airfield Lighting Product Line                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Proceeds from sale     $ 1,000,000.0                
Percentage of revenue (as a percentage)     1.00%           1.00%    
Pre-tax loss on sale     $ 1,300,000           $ 1,300,000    
Test Systems                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Impairment charge                 0 0  
Test Systems | Held for Sale                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Total cash proceeds of divesture         $ 103,800,000            
Gain on sale, net of tax         80,100,000     $ 80,100,000      
Income taxes from divesture         $ 19,700,000     $ 19,700,000      
Test Systems | Held for Sale | Subsequent Event                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Contingent earn-outs $ 10,700,000                    
Aerospace                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Impairment charge                 $ 86,312,000 1,610,000  
Intangible asset impairment charge                   $ 6,200,000  
Building | Minimum                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Property, plant and equipment, useful life (in years)                 25 years    
Building | Maximum                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Property, plant and equipment, useful life (in years)                 40 years    
Machinery and Equipment | Minimum                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Property, plant and equipment, useful life (in years)                 4 years    
Machinery and Equipment | Maximum                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Property, plant and equipment, useful life (in years)                 10 years    
Freedom Communication Technologies, Inc.                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Business acquisition purchase price paid in cash       $ 21,800,000              
Cash acquired       $ 600,000              
Diagnosys Test Systems Limited                      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]                      
Cash purchase price   $ 7,000,000.0                  
Contingent consideration, fair value   2,500,000                  
Potential additional earn-out   $ 13,000,000.0                  
Achievement period (in years)   3 years                  
Earn-out achievement benchmark   $ 72,000,000.0