Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 147,801	$ 140,043	$ 290,973	$ 287,379
Bulk / Distributed specialty products [Member]
Disaggregation of Revenue [Line Items]
Revenue	42,624	39,462	81,268	83,786
Manufactured, blended or repackaged products [Member]
Disaggregation of Revenue [Line Items]
Revenue	104,126	99,283	207,572	201,048
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,051	1,298	2,133	2,545
Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue	61,171	68,090	132,673	143,415
Industrial [Member] | Bulk / Distributed specialty products [Member]
Disaggregation of Revenue [Line Items]
Revenue	9,313	11,599	18,137	26,612
Industrial [Member] | Manufactured, blended or repackaged products [Member]
Disaggregation of Revenue [Line Items]
Revenue	51,155	55,607	112,997	115,078
Industrial [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	703	884	1,539	1,725
Water Treatment [Member]
Disaggregation of Revenue [Line Items]
Revenue	49,540	45,868	89,254	89,120
Water Treatment [Member] | Bulk / Distributed specialty products [Member]
Disaggregation of Revenue [Line Items]
Revenue	4,358	4,971	8,233	9,679
Water Treatment [Member] | Manufactured, blended or repackaged products [Member]
Disaggregation of Revenue [Line Items]
Revenue	44,838	40,487	80,344	78,637
Water Treatment [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	344	410	677	804
Health and Nutrition [Member]
Disaggregation of Revenue [Line Items]
Revenue	37,090	26,085	69,046	54,844
Health and Nutrition [Member] | Bulk / Distributed specialty products [Member]
Disaggregation of Revenue [Line Items]
Revenue	28,953	22,892	54,898	47,495
Health and Nutrition [Member] | Manufactured, blended or repackaged products [Member]
Disaggregation of Revenue [Line Items]
Revenue	8,133	3,189	14,231	7,333
Health and Nutrition [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 4	$ 4	$ (83)	$ 16