Restructuring (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 28, 2014	Dec. 31, 2013
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		$ 2,916
Restructuring Charges	1,722
Payments for Restructuring	(3,847)
Restructuring Reserve, Ending Balance	791	2,916
Cost of Goods Sold [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	696
Research, development and engineering expense [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	955
Selling, General and Administrative Expenses [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	71
Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		2,421
Severance Costs	1,683
Payments for Restructuring	(3,647)
Restructuring Reserve, Ending Balance	457	2,421
Lease abandonment costs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		495
Lease abandonment costs	39
Payments for Restructuring	(200)
Restructuring Reserve, Ending Balance	$ 334	$ 495