Restructuring (Changes in Restructuring Accruals) (Details) - Realignment of Office Furniture Facilities and Exit of Business Line $ in Thousands	6 Months Ended
	Jul. 01, 2017 USD ($)
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2016	$ 2,704
Restructuring charges, excluding accelerated depreciation	2,542
Cash payments	(2,747)
Balance as of July 1, 2017	2,499
Severance
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2016	2,704
Restructuring charges, excluding accelerated depreciation	895
Cash payments	(1,699)
Balance as of July 1, 2017	1,900
Facility Exit Costs & Other
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2016	0
Restructuring charges, excluding accelerated depreciation	1,647
Cash payments	(1,048)
Balance as of July 1, 2017	$ 599