Restructuring Activities (Detail) $ in Thousands	1 Months Ended	12 Months Ended
	May 31, 2016 facility	Dec. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Restructuring Cost and Reserve [Line Items]
Number of facilities closed | facility	1
Restructuring charges accrued during period		$ 1,903	$ 654
Restructuring Reserve [Roll Forward]
Beginning balance		1,903
Charges		182
Cash Payments		(1,453)
Change in Estimates		22
Ending balance		654
Severance and benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges accrued during period		722	0
Restructuring Reserve [Roll Forward]
Beginning balance		722
Charges		49
Cash Payments		(779)
Change in Estimates		8
Ending balance		0
Lease termination
Restructuring Cost and Reserve [Line Items]
Restructuring charges accrued during period		1,181	654
Restructuring Reserve [Roll Forward]
Beginning balance		1,181
Charges		133
Cash Payments		(674)
Change in Estimates		14
Ending balance		654
Structural Systems | Severance benefits and loss on early exit from leases
Restructuring Cost and Reserve [Line Items]
Restructuring charges accrued during period		600	600
Restructuring Reserve [Roll Forward]
Ending balance		600
Restructuring Plan, 2015 | Severance benefits and loss on early exit from leases
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred to date			2,200
Restructuring Plan, 2016 | Severance benefits and loss on early exit from leases
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred to date			200
Restructuring Plan, 2016 | Electronic Systems | Lease termination
Restructuring Cost and Reserve [Line Items]
Restructuring charges accrued during period		100	$ 100
Restructuring Reserve [Roll Forward]
Ending balance		$ 100