Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Jan. 02, 2021	Dec. 28, 2019
Deferred tax assets:
Loss contingency reserves	$ 9,805	$ 11,193
Employee benefits	13,027	12,236
Pension liability	13,053	13,049
Intangible assets amortization, including taxable goodwill	1,474	1,485
Interest expense carryforwards	402	12,361
Tax loss carryforwards	68,730	80,195
Tax credit carryforwards	6,610	5,653
Operating lease liabilities	38,930	33,549
Inventory	5,935	5,185
Accrued liabilities and other	12,925	13,677
Total gross deferred tax assets	170,891	188,583
Less valuation allowance	(24,228)	(24,759)
Net deferred tax assets	146,663	163,824
Deferred tax liabilities:
Intangible assets amortization, including taxable goodwill	(169,277)	(157,332)
Property, plant and equipment depreciation	(133,712)	(144,911)
Investment in DGD Joint Venture	(52,238)	(54,287)
Operating lease assets	(38,049)	(32,233)
Tax on unremitted foreign earnings	(10,234)	(6,139)
Other	(2,685)	(2,459)
Total gross deferred tax liabilities	(406,195)	(397,361)
Net deferred tax liability	(259,532)	(233,537)
Non-current deferred tax asset	16,676	14,394
Non-current deferred tax liability	$ (276,208)	$ (247,931)