Comprehensive Income Reclassifications (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
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales and operating expenses												$ 1,261,101		$ 1,232,604		$ 1,268,221
Interest expense												38,108		24,054		37,163
Amortization of prior service cost												(142)		(103)		(90)
Amortization of actuarial loss												5,202		4,756		2,724
Income from operations before income taxes	23,078	[1]	45,024	[1]	42,753	[1]	52,823	44,908	59,307	57,829	44,741	163,678		206,785		272,294
Income taxes												(54,711)		(76,015)		(102,876)
Net income	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
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income												111		(3,911)		(2,706)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivative Instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from operations before income taxes												5,527		(1,527)		(1,604)
Income taxes												(2,145)		592		621
Net income												3,382		(935)		(983)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivative Instruments | Natural Gas Swap [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales and operating expenses												41		(1,267)		(441)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivative Instruments | Corn Option [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales and operating expenses												5,486		0		0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivative Instruments | Interest Rate Swap [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense												0		(260)		(1,163)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Defined Benefit Pension Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service cost												(142)	[2]	(103)	[2]	(90)	[2]
Amortization of actuarial loss												(5,202)	[2]	(4,756)	[2]	(2,724)	[2]
Income from operations before income taxes												(5,344)		(4,859)		(2,814)
Income taxes												2,073		1,883		1,091
Net income												$ (3,271)		$ (2,976)		$ (1,723)

[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.

[2] These items are included in the computation of net periodic pension cost. See Note 16 Employee Benefit Plans for additional information.