Restructuring, Reorganization, Relocation and Severance (Details) (USD $)	3 Months Ended		6 Months Ended			3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jul. 01, 2012	Jun. 30, 2013	Jul. 01, 2012	Jun. 30, 2013 Group Structure Reorganization [Member]	Dec. 31, 2012 Group Structure Reorganization [Member]	Jun. 30, 2013 Group Structure Reorganization [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring, reorganization, relocation and severance	$ 395,000	$ 0	$ 1,090,000	$ 0	$ 1,090,000	$ 2,900,000
Restructuring Reserve [Roll Forward]
Beginning accrued liability			2,692,000		2,692,000
Restructuring, reorganization, relocation and severance	395,000	0	1,090,000	0	1,090,000	2,900,000
Expenditures			(2,744,000)		(2,744,000)
Write-offs and adjustments			16,000		16,000
Ending accrued liability	1,054,000		1,054,000		1,054,000
Expected additional cost of restructuring plan							0
Expected total cost of restructuring plan							$ 4,000,000