Investment in Unconsolidated Subsidiary (Assets, Liabilities and members' equity) (Details) - USD ($) $ in Thousands	Jul. 03, 2021	Jun. 30, 2021	Apr. 03, 2021	Jan. 02, 2021	Dec. 31, 2020	Jun. 27, 2020	Mar. 28, 2020	Dec. 28, 2019
ASSETS
Assets, Current	$ 1,022,580			$ 986,994
Property, Plant and Equipment, Net	1,846,814			1,863,814
Other assets	61,000			60,682
Segment Assets	5,833,323			5,613,331
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current portion of long-term debt	41,603			27,538
Other non-current liabilities	115,510			117,371
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	3,183,810		$ 3,029,946	2,954,209		$ 2,698,354	$ 2,608,442	$ 2,643,350
Liabilities and Equity	$ 5,833,323			$ 5,613,331
Diamond Green Diesel Holdings LLC Joint Venture [Member] | Equity Method Investment, Nonconsolidated Investee or Group of Investees
ASSETS
Assets, Current		$ 464,631			$ 383,557
Property, Plant and Equipment, Net		1,727,979			1,238,726
Other assets		35,369			36,082
Segment Assets		2,227,979			1,658,365
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current portion of long-term debt		581			517
Other Liabilities, Current		205,484			99,787
Long-term Debt, Excluding Current Maturities		8,635			8,705
Other non-current liabilities		8,555			3,758
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		2,004,724			1,545,598
Liabilities and Equity		$ 2,227,979			$ 1,658,365