Comprehensive Income Reclassifications (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jan. 03, 2015	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 28, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Jan. 03, 2015		Dec. 28, 2013		Dec. 29, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales and operating expenses		$ 22,900	$ 24,300	$ 14,900	$ 19,200	$ 19,300	$ 19,900	$ 20,200	$ 3,123,171		$ 1,339,819		$ 1,303,727
Interest expense									135,416		38,108		24,054
Amortization of prior service cost									(23)		(142)		(103)
Amortization of actuarial loss									2,078		5,202		4,756
Income taxes									(13,141)		(54,711)		(76,015)
Net income	69,943	14,318	32,757	(52,803)	22,493	27,651	26,418	32,405	64,215		108,967		130,770
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income									1,201		111		(3,911)
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									4,064		5,527		(1,527)
Income taxes									(1,577)		(2,145)		592
Net income									2,487		3,382		(935)
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									196		41		(1,267)
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									3,868		5,486		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		0		(260)
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									(23)	[1]	(142)	[1]	(103)	[1]
Amortization of actuarial loss									(2,078)	[1]	(5,202)	[1]	(4,756)	[1]
Income from operations before income taxes									(2,101)		(5,344)		(4,859)
Income taxes									815		2,073		1,883
Net income									$ (1,286)		$ (3,271)		$ (2,976)

[1] These items are included in the computation of net periodic pension cost. See Note 15 Employee Benefit Plans for additional information.