Annual report pursuant to Section 13 and 15(d)

Property, Plant and Equipment - Summary of Property, Plant and Equipment (Details)

v3.20.4
Property, Plant and Equipment - Summary of Property, Plant and Equipment (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2020
Property, Plant and Equipment [Line Items]    
Property, plant and equipment gross $ 205,180 $ 210,671
Less Accumulated Depreciation 92,681 103,993
Total Property, Plant and Equipment, Net 112,499 106,678
Aerospace    
Property, Plant and Equipment [Line Items]    
Impairment of long-lived assets held-for-use 2,300  
Held for Sale | Test Systems    
Property, Plant and Equipment [Line Items]    
Net property, plant and equipment 1,500  
Land    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment gross 9,802 9,891
Building and Improvements    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment gross 74,723 75,493
Machinery and Equipment    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment gross 115,202 119,444
Construction in Progress    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment gross $ 5,453 $ 5,843