Summary of Restructuring Costs for Each Segment and Unallocated Corporate Costs (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended				20 Months Ended
	Jun. 28, 2013		Jun. 29, 2012		Jun. 28, 2013		Jun. 29, 2012		Jun. 28, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	$ 1,114		$ 2,451		$ 3,166		$ 4,668
Fiscal Year 2011
Restructuring Cost and Reserve [Line Items]
Cumulative Costs for Plan									10,255
Restructuring Costs	606		2,444		2,231		4,652
Fiscal Year 2011 | Laser Products
Restructuring Cost and Reserve [Line Items]
Cumulative Costs for Plan									8,044
Restructuring Costs	503		1,838		1,969		3,964
Fiscal Year 2011 | Precision Technologies
Restructuring Cost and Reserve [Line Items]
Cumulative Costs for Plan									746
Restructuring Costs	20		170		53		200
Fiscal Year 2011 | Unallocated Restructuring Costs
Restructuring Cost and Reserve [Line Items]
Cumulative Costs for Plan									1,465	[1]
Restructuring Costs	83	[1]	436	[1]	209	[1]	488	[1]
2013 Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	508				927
2013 Restructuring | Laser Products
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	171				171
2013 Restructuring | Precision Technologies
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	282				701
2013 Restructuring | Unallocated Restructuring Costs
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	$ 55	[1]			$ 55	[1]

[1] Represents consulting and severance restructuring costs related to corporate and shared service functions.