Employee Retirement Plans - Assets of Plans Invested in Classes of Securities (Details)	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2012	Dec. 31, 2011
Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	100.00%
Percentage of Plan Assets	100.00%		100.00%
Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	100.00%
Percentage of Plan Assets	100.00%		100.00%
Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	100.00%
Percentage of Plan Assets		100.00%	100.00%
Equity [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	48.00%
Percentage of Plan Assets	52.00%		49.00%
Equity [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	48.00%
Percentage of Plan Assets	52.00%		51.00%
Equity [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	50.00%
Percentage of Plan Assets	71.00%		66.00%
Fixed Income [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	40.00%
Percentage of Plan Assets	36.00%		37.00%
Fixed Income [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	40.00%
Percentage of Plan Assets	37.00%		37.00%
Fixed Income [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	50.00%
Percentage of Plan Assets	26.00%		27.00%
Money Market [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	4.00%
Percentage of Plan Assets	6.00%		5.00%
Money Market [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	4.00%
Percentage of Plan Assets	5.00%		4.00%
Money Market [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	0.00%
Percentage of Plan Assets	3.00%		7.00%
Other (real estate & commodities) [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	8.00%
Percentage of Plan Assets	6.00%		9.00%
Other (real estate & commodities) [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	8.00%
Percentage of Plan Assets	6.00%		8.00%
Other (real estate & commodities) [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	0.00%
Percentage of Plan Assets	0.00%		0.00%