Summary of Restructuring Costs for Each Segment and Unallocated Corporate Costs (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended					14 Months Ended	12 Months Ended		14 Months Ended	12 Months Ended		14 Months Ended	12 Months Ended				14 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Fiscal Year 2011	Dec. 31, 2011 Fiscal Year 2011	Dec. 31, 2012 Fiscal Year 2011	Dec. 31, 2012 Fiscal Year 2011 Laser Products	Dec. 31, 2011 Fiscal Year 2011 Laser Products	Dec. 31, 2012 Fiscal Year 2011 Laser Products	Dec. 31, 2012 Fiscal Year 2011 Precision Motion and Technologies	Dec. 31, 2011 Fiscal Year 2011 Precision Motion and Technologies	Dec. 31, 2012 Fiscal Year 2011 Precision Motion and Technologies	Dec. 31, 2012 Fiscal Year 2011 Unallocated Restructuring Costs		Dec. 31, 2011 Fiscal Year 2011 Unallocated Restructuring Costs		Dec. 31, 2012 Fiscal Year 2011 Unallocated Restructuring Costs		Dec. 31, 2012 Fiscal Year 2012	Dec. 31, 2012 Fiscal Year 2012 Laser Products	Dec. 31, 2012 Fiscal Year 2012 Precision Motion and Technologies	Dec. 31, 2012 Fiscal Year 2012 Unallocated Restructuring Costs
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	$ 8,051	$ 2,048	$ 391	$ 6,057	$ 1,967	$ 8,024	$ 4,422	$ 1,643	$ 6,065	$ 491	$ 212	$ 703	$ 1,144	[1]	$ 112	[1]	$ 1,256	[1]	$ 1,758	$ 501	$ 951	$ 306	[1]

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