Guarantor Financial Information Guarantor Financial Information Condensed Consolidating Statements of Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended											12 Months Ended
	Dec. 28, 2013		Sep. 28, 2013		Jun. 29, 2013		Mar. 30, 2013	Dec. 29, 2012	Sep. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Net income/(loss)	$ 22,493	[1]	$ 27,651	[1]	$ 26,418	[1]	$ 32,405	$ 28,802	$ 37,172	$ 36,225	$ 28,571	$ 108,967	$ 130,770	$ 169,418
Foreign currency translation												(14,502)	0	0
Pension adjustments												15,140	(1,169)	(10,146)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent												1,906	(425)	(9,916)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent												110,873	130,345	159,502
Natural Gas Swap [Member]
Derivative adjustments												127	391	(482)
Corn Option [Member]
Derivative adjustments												1,141	194	0
Interest Rate Swap [Member]
Derivative adjustments												0	159	712
Issuer [Member]
Net income/(loss)												108,967	130,770	169,418
Foreign currency translation												0
Pension adjustments												15,060	(1,169)	(10,146)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent												16,328	(425)	(9,916)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent												125,295	130,345	159,502
Issuer [Member] | Natural Gas Swap [Member]
Derivative adjustments												127	391	(482)
Issuer [Member] | Corn Option [Member]
Derivative adjustments												1,141	194
Issuer [Member] | Interest Rate Swap [Member]
Derivative adjustments													159	712
Guarantors [Member]
Net income/(loss)												107,317	121,321	146,584
Foreign currency translation												0
Pension adjustments												0	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent												0	0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent												107,317	121,321	146,584
Guarantors [Member] | Natural Gas Swap [Member]
Derivative adjustments												0	0	0
Guarantors [Member] | Corn Option [Member]
Derivative adjustments												0	0
Guarantors [Member] | Interest Rate Swap [Member]
Derivative adjustments													0	0
Non-guarantors [Member]
Net income/(loss)												(2,139)	(1,368)	(634)
Foreign currency translation												(14,502)
Pension adjustments												80	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent												(14,422)	0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent												(16,561)	(1,368)	(634)
Non-guarantors [Member] | Natural Gas Swap [Member]
Derivative adjustments												0	0	0
Non-guarantors [Member] | Corn Option [Member]
Derivative adjustments												0	0
Non-guarantors [Member] | Interest Rate Swap [Member]
Derivative adjustments													0	0
Eliminations [Member]
Net income/(loss)												(105,178)	(119,953)	(145,950)
Foreign currency translation												0
Pension adjustments												0	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent												0	0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent												(105,178)	(119,953)	(145,950)
Eliminations [Member] | Natural Gas Swap [Member]
Derivative adjustments												0	0	0
Eliminations [Member] | Corn Option [Member]
Derivative adjustments												0	0
Eliminations [Member] | Interest Rate Swap [Member]
Derivative adjustments													$ 0	$ 0

[1] Included in net income are $0.8 million in transaction costs in the second quarter of fiscal 2013, $8.3 million in transaction costs in the third quarter of fiscal 2013 and $14.2 million in the fourth quarter relating to the Terra Transaction, Rothsay Acquisition and the VION Acquisition.