Business Segments (Narrative) (Details) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 30, 2017 USD ($) segment	Sep. 30, 2017 USD ($)	Jul. 01, 2017 USD ($)	Apr. 01, 2017 USD ($)	Dec. 31, 2016 USD ($)	Oct. 01, 2016 USD ($)	Jul. 02, 2016 USD ($)	Apr. 02, 2016 USD ($)	Dec. 29, 2018 USD ($)	Dec. 30, 2017 USD ($) segment	Dec. 31, 2016 USD ($)	Jan. 02, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of Business Segments | segment		3									3
Net Sales		$ 952,549	$ 936,262	$ 894,930	$ 878,510	$ 885,758	$ 852,018	$ 875,777	$ 778,375		$ 3,662,251	$ 3,391,928	$ 3,391,255
Capital expenditures:	[1]										274,168	243,523	229,848
Fuel Ingredients [Member]
Segment Reporting Information [Line Items]
Net Sales											265,783	247,058	228,195
Capital expenditures:											$ 24,707	$ 22,323	$ 19,478
Scenario, Forecast [Member] | Fuel Ingredients [Member]
Segment Reporting Information [Line Items]
Income Tax Credits and Adjustments										$ 12,600

[1] Excludes immaterial capital assets acquired by acquisition in fiscal 2017, fiscal 2016 and fiscal 2015.