Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,390	$ 3,945
Accumulated Amortization	(3,771)	(3,320)
Net Carrying Amount	$ 619	$ 625
Weighted Average Remaining Useful Life	16 years 9 months 18 days	16 years 3 months 18 days
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,711	$ 2,436
Accumulated Amortization	(2,711)	(2,436)
Brands Associated with Acquired Cell Lines [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	559	502
Accumulated Amortization	(190)	(158)
Net Carrying Amount	$ 369	$ 344
Weighted Average Remaining Useful Life	26 years 4 months 24 days	27 years 4 months 24 days
Product Licenses [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 944	$ 849
Accumulated Amortization	(694)	(568)
Net Carrying Amount	$ 250	$ 281
Weighted Average Remaining Useful Life	2 years 7 months 6 days	3 years 6 months
Other Intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 176	$ 158
Accumulated Amortization	$ (176)	$ (158)