Asset Retirement Obligations Asset Retirement Obligations (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Jan. 02, 2011	Jan. 02, 2010
Asset Retirement Obligations [Line Items]
Asset Retirement Obligations Assets Held-for-sale Noncurrent	$ 1,277,000	$ 2,119,000
Asset Retirement Obligation, Current	7,500,000	11,700,000
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation: Beginning of Year	82,849,000		82,849,000	102,080,000
Asset Retirement Obligation, Liabilities Incurred	5,465,000	4,738,000
Asset Retirement Obligation, Liabilities Settled	(8,365,000)	(30,523,000)
Asset Retirement Obligation, Accretion Expense	5,948,000	5,583,000
Asset Retirement Obligation, Revision of Estimate	10,009,000	971,000
Asset Retirement Obligation: End of Year	$ 95,906,000	$ 82,849,000	$ 82,849,000	$ 102,080,000
Low End of Discount Rate Range [Member]
Asset Retirement Obligations [Line Items]
Discount Rate Used for ARO Present Value	6.50%
High End of Discount Rate Range [Member]
Asset Retirement Obligations [Line Items]
Discount Rate Used for ARO Present Value	12.00%