Derivative Financial Instruments Schedule of Offsetting of Derivate Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2013	Dec. 31, 2012
Offsetting Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 1,613	$ 1,619
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	1,613	1,619
Derivative Liability, Fair Value, Gross Asset	(228)	(1,144)
Derivative, Collateral, Right to Reclaim Cash	0	0
Derivative Liability	1,385	475
Barclays [Member]
Offsetting Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability	711	1,401
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	711	1,401
Derivative Liability, Fair Value, Gross Asset	(159)	(1,107)
Derivative, Collateral, Right to Reclaim Cash	0	0
Derivative Liability	552	294
Wells Fargo Bank [Member]
Offsetting Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability	902	218
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	902	218
Derivative Liability, Fair Value, Gross Asset	(69)	(37)
Derivative, Collateral, Right to Reclaim Cash	0	0
Derivative Liability	$ 833	$ 181