Income Taxes - Net Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 28, 2014	Dec. 29, 2013
Deferred tax assets
Retirement, postemployment and deferred compensation plans	$ 320,174	$ 251,082
Accruals for other employee benefits, compensation, insurance and other	42,294	35,596
Accounts receivable allowances	1,746	1,478
Net operating losses	46,726	57,885
Other	41,186us-gaap_DeferredTaxAssetsOther	63,821us-gaap_DeferredTaxAssetsOther
Gross deferred tax assets	452,126us-gaap_DeferredTaxAssetsGross	409,862us-gaap_DeferredTaxAssetsGross
Valuation allowance	(41,136)	(42,295)
Net deferred tax assets	410,990us-gaap_DeferredTaxAssetsNet	367,567us-gaap_DeferredTaxAssetsNet
Deferred tax liabilities
Property, plant and equipment	64,056	75,661
Intangible assets	11,607	11,902
Investments in joint ventures	13,971	19,625
Other	5,129us-gaap_DeferredTaxLiabilitiesOther	14,531us-gaap_DeferredTaxLiabilitiesOther
Gross deferred tax liabilities	94,763us-gaap_DeferredTaxLiabilities	121,719us-gaap_DeferredTaxLiabilities
Net deferred tax asset	316,227us-gaap_DeferredTaxAssetsLiabilitiesNet	245,848us-gaap_DeferredTaxAssetsLiabilitiesNet
Deferred tax asset – current	63,640	65,859
Deferred tax asset – long-term	$ 252,587	$ 179,989
Valuation allowance, period for recoverability measurement	3 years

The tax effect as of the balance sheet date of the amount of estimated future tax deductions arising from retirement benefits, postemployment benefits, and deferred compensation plans which can only be deducted for tax purposes when actual costs are incurred, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the deduction to be taken.

No definition available.