Employee Benefit Plans (Narrative) (Details) (USD $)	12 Months Ended				12 Months Ended																		12 Months Ended					12 Months Ended			12 Months Ended	1 Months Ended	12 Months Ended
	Dec. 29, 2012 plan	Dec. 31, 2011	Jan. 01, 2011	Jan. 03, 2009	Dec. 29, 2012 Minimum [Member]	Dec. 29, 2012 Maximum [Member]	Dec. 29, 2012 Hourly 401K Savings Plan [Member]	Dec. 31, 2011 Hourly 401K Savings Plan [Member]	Jan. 01, 2011 Hourly 401K Savings Plan [Member]	Dec. 29, 2012 Hourly 401K Savings Plan [Member] Minimum [Member]	Dec. 29, 2012 Hourly 401K Savings Plan [Member] Maximum [Member]	Dec. 31, 2011 Hourly 401K Savings Plan [Member] Maximum [Member]	Dec. 29, 2012 Salaried 401(k) Savings Plan [Member]	Dec. 31, 2011 Salaried 401(k) Savings Plan [Member]	Jan. 01, 2011 Salaried 401(k) Savings Plan [Member]	Dec. 29, 2012 Salaried 401(k) Savings Plan [Member] Minimum [Member]	Dec. 31, 2011 Salaried 401(k) Savings Plan [Member] Minimum [Member]	Dec. 29, 2012 Salaried 401(k) Savings Plan [Member] Maximum [Member]	Dec. 31, 2011 Salaried 401(k) Savings Plan [Member] Maximum [Member]	Dec. 31, 2011 Griffins Defined Contribution Plans [Member]	Dec. 29, 2012 Small Companies [Member] Minimum [Member]	Dec. 29, 2012 Small Companies [Member] Maximum [Member]	Dec. 29, 2012 Geographic Concentration Risk [Member] Maximum [Member]	Dec. 29, 2012 Fixed Income Securities [Member]	Dec. 31, 2011 Fixed Income Securities [Member]	Dec. 29, 2012 Equity Funds [Member]	Dec. 29, 2012 Fixed Income Funds [Member]	Dec. 29, 2012 Equity Securities, International [Member] Emerging Market [Member]	Dec. 29, 2012 Equity Securities [Member]	Dec. 31, 2011 Equity Securities [Member]	Dec. 29, 2012 Defined Benefit Plans Assets, Total [Member] Investment [Domain]	Jul. 31, 2005 Central States, Southeast and Southwest Areas Pension Plan [Member]	Dec. 29, 2012 Central States, Southeast and Southwest Areas Pension Plan [Member]		Dec. 31, 2011 Central States, Southeast and Southwest Areas Pension Plan [Member]		Jan. 01, 2011 Central States, Southeast and Southwest Areas Pension Plan [Member]
Employee Benefit Plans [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent							25.00%	100.00%					25.00%
Defined Contribution Plan, Pay Period Maximum Contribution Per Employee, Percent							6.00%						6.00%
Defined Contribution Plan, Maximum Annual Contribution Per Employee, Percent										2.00%	5.00%					3.00%	2.00%	6.00%	5.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum																								35.00%					20.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum																								80.00%					65.00%
Defined Contribution Plan, Employer Matching Contribution Per Pay Period, First Amount Of Participants Deferrals								$ 10
Defined Contribution Plan, Contributions by Plan Participants												520
Defined Contribution Plan, Maximum Annual Contribution Per Employee, Amount								520
Defined Contribution Plan, Employer Contribution Amount							2,300,000	700,000	700,000				4,900,000	1,500,000	1,500,000					500,000
Equity Securities	100.00%	100.00%																						38.70%	40.30%	60.00%	40.00%		61.30%	59.70%
Period of Return Of Double and Single Digit Returns	10 years
Investment Horizon of Greater Than	10 years
Expected long-term rate of return on assets	7.35%	7.85%	7.85%
Capitalization, Long-term Debt and Equity																					300,000,000	2,000,000,000
Concentration Risk, Percentage																							5.00%					10.00%			1.50%
Investment Objectives Achievement Period					5 years	7 years
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	400,000
Multiemployer Plan, Contributions To Individual Plan, Percent						5.00%
Number Of Multiemployer Plans, Withdrawal Obligation Could Be Material	2
Multiemployer Plan, Period Contributions	3,200,000	3,100,000	2,900,000																														746,000	[1],[2]	705,000	[1],[2]	630,000	[1],[2]
Number of Multiemployer Plans, Certified Red Zone	4
Number of Multiemployer Plans, Certified Yellow Zone	1
Number of Multiemployer Plans, Certified Orange Zone	1
Multiemployer Plan, Withdrawal Obligation	$ 1,000,000	$ 1,200,000		$ 3,200,000
Multiemployer Plans, IRS Extended Amortization Period																																10 years

[1] In July 2005 this plan received a 10 year extension from the IRS for amortizing unfunded liabilities.

[2] The Company has several processing plants that participate in the Central States, Southeast and Southwest Areas Pension Plan under collective bargaining agreements that require minimum funding contributions. Certain of these agreements have expired and are being renegotiated with others having expiration dates through December 15, 2014.