Restatement Restated Balance Sheet (Details) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2013	Dec. 31, 2012	Sep. 30, 2012
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated depreciation	$ (1,245,597)	$ (1,162,213)	$ (1,183,589)
Total assets	2,101,047	2,019,865	2,081,992
Deferred Tax Liability	157,603	153,792	140,113
Limited Partners' Equity	206,428	177,660	207,933
As previously filed [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated depreciation			(1,175,744)
Total assets			2,089,837
Deferred Tax Liability			143,094
Limited Partners' Equity			212,797
Correction [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated depreciation			(7,845)
Total assets			(7,845)
Deferred Tax Liability			(2,981)
Limited Partners' Equity			$ (4,864)