Business Segments (Narrative) (Details) $ in Thousands		12 Months Ended
		Dec. 28, 2019 USD ($) segment	Dec. 29, 2018 USD ($)	Dec. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of Business Segments | segment		3
Capital expenditures:	[1]	$ 359,498	$ 321,896	$ 274,168
Fuel Ingredients [Member]
Segment Reporting Information [Line Items]
Capital expenditures:		$ 23,964	$ 27,121	$ 24,707

[1] Excludes capital assets acquired by acquisition in fiscal 2018 of approximately $31.6 million and excludes immaterial capital assets acquired by acquisition in fiscal 2017.