Summary of Restructuring Costs for Each Segment and Unallocated Corporate Costs (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				17 Months Ended
	Mar. 29, 2013		Mar. 30, 2012		Mar. 29, 2013
Restructuring Cost and Reserve [Line Items]
Cumulative Costs for Plan					$ 9,649
Restructuring Costs	2,051		2,217
Fiscal Year 2011
Restructuring Cost and Reserve [Line Items]
Cumulative Costs for Plan					9,649
Restructuring Costs	1,625		2,208
Fiscal Year 2011 | Laser Products
Restructuring Cost and Reserve [Line Items]
Cumulative Costs for Plan					7,541
Restructuring Costs	1,466		2,127
Fiscal Year 2011 | Precision Technologies
Restructuring Cost and Reserve [Line Items]
Cumulative Costs for Plan					726
Restructuring Costs	33		29
Fiscal Year 2011 | Unallocated Restructuring Costs
Restructuring Cost and Reserve [Line Items]
Cumulative Costs for Plan					1,382	[1]
Restructuring Costs	$ 126	[1]	$ 52	[1]

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