Restructuring Costs Related To Sale Of Commercial Product Portfolio (Details) $ in Thousands		3 Months Ended
	Mar. 01, 2019 employee	Mar. 31, 2020 USD ($)	May 31, 2019 USD ($)	Mar. 31, 2019 USD ($)
Restructuring Cost and Reserve [Line Items]
Number of employees terminated or given notice of termination | employee	87
Revenue from contract with customer		$ 0		$ 0
Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring costs expected cost remaining		$ 200		1,100
Employees terminated March 1, 2019 | Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring costs				8,300
Employees terminated March 1, 2019 | Employee severance | Income from discontinued operations, net of income taxes
Restructuring Cost and Reserve [Line Items]
Restructuring costs				6,300
Employees terminated March 1, 2019 | Employee severance | Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring costs				1,500
Employees terminated March 1, 2019 | Employee severance | Research and development
Restructuring Cost and Reserve [Line Items]
Restructuring costs				500
Employees given notice of May 31, 2019 | Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring costs			$ 500	200
Acrotech | Service [Member]
Restructuring Cost and Reserve [Line Items]
Revenue from contract with customer				$ 200