Restructuring Activities (Detail) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	May 31, 2016 facility	Dec. 31, 2017 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Restructuring Cost and Reserve [Line Items]
Number of facilities closed | facility	1
Restructuring Reserve [Roll Forward]
Beginning balance				$ 654
Charges		$ 8,800		8,360	$ 182	$ 2,125
Ending balance		2,725		2,725	654
Severance and benefits
Restructuring Reserve [Roll Forward]
Beginning balance				0
Ending balance		2,659		2,659	0
Modification of stock-based compensation awards
Restructuring Reserve [Roll Forward]
Beginning balance				0
Ending balance		0		0	0
Lease termination
Restructuring Reserve [Roll Forward]
Beginning balance				654
Ending balance		66		66	654
Property and equipment impairment due to restructuring
Restructuring Reserve [Roll Forward]
Beginning balance				0
Ending balance		0		0	0
Inventory write down
Restructuring Reserve [Roll Forward]
Beginning balance				0
Ending balance		0		0	$ 0
Electronic Systems
Restructuring Cost and Reserve [Line Items]
Accrued severance and loss on early exit		1,000		1,000
Electronic Systems | Severance and benefits
Restructuring Reserve [Roll Forward]
Charges				1,200
Structural Systems
Restructuring Cost and Reserve [Line Items]
Inventory Write-down				500
Accrued severance and loss on early exit		1,300		1,300
Structural Systems | Severance and benefits
Restructuring Reserve [Roll Forward]
Charges				1,700
Corporate Segment
Restructuring Cost and Reserve [Line Items]
Accrued severance and loss on early exit		400		400
Corporate Segment | Severance and benefits
Restructuring Reserve [Roll Forward]
Charges				400
Corporate Segment | Modification of stock-based compensation awards
Restructuring Reserve [Roll Forward]
Charges				1,400
Restructuring Plan, 2017
Restructuring Reserve [Roll Forward]
Charges				8,774
Cash Payments				(1,348)
Non-Cash Payments				5,419
Change in Estimates				64
Restructuring Plan, 2017 | Severance and benefits
Restructuring Reserve [Roll Forward]
Charges				3,337
Cash Payments				(678)
Non-Cash Payments				0
Change in Estimates				0
Restructuring Plan, 2017 | Modification of stock-based compensation awards
Restructuring Reserve [Roll Forward]
Charges				1,334
Cash Payments				0
Non-Cash Payments				1,334
Change in Estimates				0
Restructuring Plan, 2017 | Lease termination
Restructuring Reserve [Roll Forward]
Charges				18
Cash Payments				(670)
Non-Cash Payments				0
Change in Estimates				64
Restructuring Plan, 2017 | Property and equipment impairment due to restructuring
Restructuring Reserve [Roll Forward]
Charges				3,607
Cash Payments				0
Non-Cash Payments				3,607
Change in Estimates				0
Restructuring Plan, 2017 | Inventory write down
Restructuring Reserve [Roll Forward]
Charges				478
Cash Payments				0
Non-Cash Payments				478
Change in Estimates				0
Restructuring Plan, 2016 | Severance and benefits
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred to date		200		200
Restructuring Plan, 2016 | Electronic Systems
Restructuring Reserve [Roll Forward]
Ending balance		100		100
Restructuring Plan, 2015 | Severance and benefits
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred to date		2,200		2,200
Minimum | Restructuring Plan, 2017
Restructuring Cost and Reserve [Line Items]
Expected restructuring cost		19,000		19,000
Maximum | Restructuring Plan, 2017
Restructuring Cost and Reserve [Line Items]
Expected restructuring cost		$ 22,000		$ 22,000
Scenario, Forecast | Restructuring Plan, 2017
Restructuring Reserve [Roll Forward]
Effect on Future Earnings, Amount			$ 14,000