Summary of Restructuring Costs for each Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2012	Sep. 30, 2011	Sep. 28, 2012	Sep. 30, 2011
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	$ 2,728	$ 14	$ 7,396	$ 74
Fiscal Year 2012
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	1,711		1,711
Fiscal Year 2012 | Laser Products
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	501		501
Fiscal Year 2012 | Precision Motion and Technologies
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	885		885
Fiscal Year 2012 | Unallocated Restructuring Costs
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	$ 325		$ 325