Restructuring Activities (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2019	Nov. 01, 2017
Restructuring Reserve [Roll Forward]
Beginning balance	$ 483	$ 654
Charges		0
Cash Payments		(235)
Change in Estimates		64
Ending balance		483
Lease termination
Restructuring Reserve [Roll Forward]
Beginning balance	483	654
Charges		0
Cash Payments		(235)
Change in Estimates		64
Ending balance		483
Restructuring Plan, 2015 | Severance benefits and loss on early exit from leases
Restructuring Cost and Reserve [Line Items]
Restructuring costs		2,200
Restructuring Plan, 2015 | Structural Systems | Severance and benefits
Restructuring Reserve [Roll Forward]
Beginning balance	400
Ending balance		400
Restructuring Plan, 2016 | Severance benefits and loss on early exit from leases
Restructuring Cost and Reserve [Line Items]
Restructuring costs		200
Restructuring Plan, 2016 | Electronic Systems | Lease termination
Restructuring Reserve [Roll Forward]
Beginning balance	100
Ending balance		$ 100
Restructuring Plan, 2017 | Forecast
Restructuring Reserve [Roll Forward]
Charges	$ 10,500
Future savings			$ 14,000
Restructuring Plan, 2017 | Subsequent Event | Minimum
Restructuring Reserve [Roll Forward]
Expected cost				$ 22,000
Restructuring Plan, 2017 | Subsequent Event | Maximum
Restructuring Reserve [Roll Forward]
Expected cost				25,000
Restructuring Plan, 2017 | Employee separation and other consolidation related expenses | Subsequent Event | Minimum
Restructuring Reserve [Roll Forward]
Expected cost				9,000
Restructuring Plan, 2017 | Employee separation and other consolidation related expenses | Subsequent Event | Maximum
Restructuring Reserve [Roll Forward]
Expected cost				10,000
Restructuring Plan, 2017 | Write-down of inventory and impairment of long-lived assets | Subsequent Event | Minimum
Restructuring Reserve [Roll Forward]
Expected cost				13,000
Restructuring Plan, 2017 | Write-down of inventory and impairment of long-lived assets | Subsequent Event | Maximum
Restructuring Reserve [Roll Forward]
Expected cost				$ 15,000