Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Dec. 31, 2019	Mar. 31, 2019
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,204	$ 4,150
Accumulated Amortization	(3,517)	(3,399)
Net Carrying Amount	$ 687	$ 751
Weighted Average Remaining Useful Life	16 years 3 months 18 days	16 years 3 months 18 days
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,596	$ 2,564
Accumulated Amortization	(2,596)	(2,564)
Brands Associated with Acquired Cell Lines [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	535	529
Accumulated Amortization	(165)	(153)
Net Carrying Amount	$ 370	$ 376
Weighted Average Remaining Useful Life	27 years 8 months 12 days	28 years 4 months 24 days
Product Licenses [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 904	$ 890
Accumulated Amortization	(587)	(515)
Net Carrying Amount	$ 317	$ 375
Weighted Average Remaining Useful Life	3 years 8 months 12 days	4 years 2 months 12 days
Other Intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 169	$ 167
Accumulated Amortization	$ (169)	$ (167)