Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 01, 2018	Jul. 02, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 149,800	$ 133,731
Bulk / Distributed products [Member]
Disaggregation of Revenue [Line Items]
Revenue	49,788
Specialty / Manufactured products [Member]
Disaggregation of Revenue [Line Items]
Revenue	97,422
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	2,590
Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue	74,018	64,027
Industrial [Member] | Bulk / Distributed products [Member]
Disaggregation of Revenue [Line Items]
Revenue	13,725
Industrial [Member] | Specialty / Manufactured products [Member]
Disaggregation of Revenue [Line Items]
Revenue	58,842
Industrial [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	1,451
Water Treatment [Member]
Disaggregation of Revenue [Line Items]
Revenue	40,869	38,224
Water Treatment [Member] | Bulk / Distributed products [Member]
Disaggregation of Revenue [Line Items]
Revenue	5,884
Water Treatment [Member] | Specialty / Manufactured products [Member]
Disaggregation of Revenue [Line Items]
Revenue	34,525
Water Treatment [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	460
Health and Nutrition [Member]
Disaggregation of Revenue [Line Items]
Revenue	34,913	$ 31,480
Health and Nutrition [Member] | Bulk / Distributed products [Member]
Disaggregation of Revenue [Line Items]
Revenue	30,179
Health and Nutrition [Member] | Specialty / Manufactured products [Member]
Disaggregation of Revenue [Line Items]
Revenue	4,055
Health and Nutrition [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 679