Derivative Financial Instruments Scheduel of Offsetting of Derivative Assets (Details) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2013	Dec. 31, 2012
Offsetting of Derivative Assets [Line Items]
Derivative Assets, Fair Value	$ 228	$ 1,144
Derivative Asset, Fair Value, Amount Offset Against Collateral	0	0
Derivative Asset, Fair Value, Net	228	1,144
Derivative Asset, Fair Value, Gross Liability	(228)	(1,144)
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset	0	0
Barclays [Member]
Offsetting of Derivative Assets [Line Items]
Derivative Assets, Fair Value	159	1,107
Derivative Asset, Fair Value, Amount Offset Against Collateral	0	0
Derivative Asset, Fair Value, Net	159	1,107
Derivative Asset, Fair Value, Gross Liability	(159)	(1,107)
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset	0	0
Wells Fargo Bank [Member]
Offsetting of Derivative Assets [Line Items]
Derivative Assets, Fair Value	69	37
Derivative Asset, Fair Value, Amount Offset Against Collateral	0	0
Derivative Asset, Fair Value, Net	69	37
Derivative Asset, Fair Value, Gross Liability	(69)	(37)
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset	$ 0	$ 0