Restructuring Costs Related To Sale Of Commercial Product Portfolio (Details) $ in Thousands		3 Months Ended			9 Months Ended
	Mar. 01, 2019 employee	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	May 31, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 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		$ 0	$ 0
Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring costs expected cost remaining		$ 100	400		$ 100	400
Employees terminated March 1, 2019 | Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring costs						5,100
Employees terminated March 1, 2019 | Employee severance | Income from discontinued operations, net of income taxes
Restructuring Cost and Reserve [Line Items]
Restructuring costs						3,900
Employees terminated March 1, 2019 | Employee severance | Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring costs						1,000
Employees terminated March 1, 2019 | Employee severance | Research and development
Restructuring Cost and Reserve [Line Items]
Restructuring costs						200
Employees given notice of May 31, 2019 | Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring costs			0	$ 500		500
Acrotech | Service [Member]
Restructuring Cost and Reserve [Line Items]
Revenue from contract with customer			$ 0			$ 700