Segment Information - Assets by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Segment Reporting Information [Line Items]
Total assets	$ 471,314	$ 347,822
Capital Expenditures	31,293	22,820	$ 14,400
Operating segments | Environmental Services
Segment Reporting Information [Line Items]
Total assets	224,657	148,192
Capital Expenditures	18,499	12,756	6,843
Operating segments | Oil Business
Segment Reporting Information [Line Items]
Total assets	171,104	142,691
Capital Expenditures	12,670	9,858	6,998
Unallocated Corporate Assets
Segment Reporting Information [Line Items]
Total assets	75,553	56,939
Capital Expenditures	$ 124	$ 206	$ 559