Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Mar. 29, 2020	Dec. 29, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 30, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Mar. 29, 2020	Mar. 31, 2019	Apr. 01, 2018
Summary of Segment Information
Sales	$ 132,413	$ 120,406	$ 140,043	$ 147,336	$ 133,051	$ 128,151	$ 145,324	$ 149,800	$ 126,990	$ 118,053	$ 125,395	$ 133,731	$ 540,198	$ 556,326	$ 504,169
Gross profit	22,648	21,478	27,994	28,797	20,674	21,033	25,772	28,457	17,806	18,840	24,115	25,999	100,917	95,936	86,760
Selling, general, and administrative expenses	14,891	14,702	14,817	14,836	14,886	14,312	14,941	14,979	14,670	14,139	14,828	15,766	59,246	59,118	59,403
Goodwill Impairment									39,116	0	0	0	0	0	39,116
Operating income	7,757	$ 6,776	$ 13,177	$ 13,961	5,788	$ 6,721	$ 10,831	$ 13,478	(35,980)	$ 4,701	$ 9,287	$ 10,233	41,671	36,818	(11,759)
Identifiable assets	376,354				367,242				376,688				376,354	367,242	376,688
Capital expenditures													24,549	12,618	19,703
Industrial [Member]
Summary of Segment Information
Sales													275,224	281,860	247,374
Gross profit													38,936	34,900	29,619
Selling, general, and administrative expenses													24,123	22,759	21,159
Goodwill Impairment															0
Operating income													14,813	12,141	8,460
Identifiable assets	173,068				162,926				165,052				173,068	162,926	165,052
Capital expenditures													14,933	7,319	10,265
Water Treatment [Member]
Summary of Segment Information
Sales													159,895	149,490	138,465
Gross profit													41,902	37,986	36,268
Selling, general, and administrative expenses													19,801	19,498	19,426
Goodwill Impairment															0
Operating income													22,101	18,488	16,842
Identifiable assets	63,506				58,274				58,513				63,506	58,274	58,513
Capital expenditures													9,160	4,506	7,228
Health and Nutrition [Member]
Summary of Segment Information
Sales													105,079	124,976	118,330
Gross profit													20,079	23,050	20,873
Selling, general, and administrative expenses													15,322	16,861	18,818
Goodwill Impairment															39,116
Operating income													4,757	6,189	(37,061)
Identifiable assets	139,780				146,042				153,123				139,780	146,042	153,123
Capital expenditures													456	793	2,210
Unallocated Amount to Segment [Member]
Summary of Segment Information
Identifiable assets	$ 13,000				$ 18,400				$ 14,300				$ 13,000	$ 18,400	$ 14,300