Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 28, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Sales	$ 143,172	$ 147,336
Gross Profit	30,976	28,797
Selling, General and Administrative Expense	15,038	14,836
Operating income	15,938	13,961
Industrial [Member]
Segment Reporting Information [Line Items]
Sales	71,502	75,325
Gross Profit	12,457	10,915
Selling, General and Administrative Expense	6,067	6,096
Operating income	6,390	4,819
Water Treatment [Member]
Segment Reporting Information [Line Items]
Sales	39,714	43,252
Gross Profit	11,339	12,091
Selling, General and Administrative Expense	5,293	4,988
Operating income	6,046	7,103
Health and Nutrition [Member]
Segment Reporting Information [Line Items]
Sales	31,956	28,759
Gross Profit	7,180	5,791
Selling, General and Administrative Expense	3,678	3,752
Operating income	$ 3,502	$ 2,039