Goodwill and Intangible Assets (Narratives) (Details)	12 Months Ended
	Mar. 31, 2021 USD ($) Reporting_Unit	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)
Finite-Lived Intangible Assets [Line Items]
Number of reporting units | Reporting_Unit	2
Goodwill	$ 331,176,000	$ 319,679,000	$ 322,816,000
Duff Norton reporting unit goodwill	9,699,000	9,593,000
Rest of products reporting unit goodwill	321,477,000	310,086,000
Impairment charges related to goodwill or intangible assets	0	0
2016	12,600,000
2017	12,600,000
2018	12,600,000
2019	12,600,000
2020	$ 12,600,000
Weighted-average amortization periods	18 years
Indefinite-lived trademark	$ 47,857,000	46,670,000
Amortization of intangibles	12,623,000	12,942,000	14,900,000
Gain (Loss) on Disposition of Property Plant Equipment	(2,638,000)	0	$ 0
Goodwill, Impaired, Accumulated Impairment Loss	$ 113,174,000	113,174,000
Trademark
Finite-Lived Intangible Assets [Line Items]
Weighted-average amortization periods	15 years
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted-average amortization periods	18 years
Acquired technology
Finite-Lived Intangible Assets [Line Items]
Weighted-average amortization periods	18 years
Other
Finite-Lived Intangible Assets [Line Items]
Weighted-average amortization periods	5 years
Goodwill [Member]
Finite-Lived Intangible Assets [Line Items]
Gain (Loss) on Disposition of Property Plant Equipment		$ 6,174,000