Restructuring Activities (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2017	Apr. 01, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges accrued during period	$ 654	$ 576
Restructuring Reserve [Roll Forward]
Beginning balance	654
Charges	0
Cash Payments	(78)
Change in Estimates	0
Ending balance	576
Severance and benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges accrued during period	0	0
Restructuring Reserve [Roll Forward]
Beginning balance	0
Charges	0
Cash Payments	0
Change in Estimates	0
Ending balance	0
Lease termination
Restructuring Cost and Reserve [Line Items]
Restructuring charges accrued during period	654	576
Restructuring Reserve [Roll Forward]
Beginning balance	654
Charges	0
Cash Payments	(78)
Change in Estimates	0
Ending balance	576
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, 2015 | Structural Systems | Severance and benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges accrued during period	500	500
Restructuring Reserve [Roll Forward]
Ending balance	500
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