Leases - Narrative (Details) $ in Millions	12 Months Ended
	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2020 USD ($) ft²	Oct. 31, 2019 USD ($) ft²
Lessee, Lease, Description [Line Items]
Rent expense under topic 840	$ 2.1	$ 0.9
Brisbane, California Office Space
Lessee, Lease, Description [Line Items]
Area leased (in sq ft) | ft²			40,232
Extension term			7 years
Letters of credit			$ 0.5	$ 0.2
Reduced letter of credit if conditions met			$ 0.2
Area subleased | ft²				20,116
Weighted average remaining lease term			5 years 8 months 12 days
Weighted average discount rate			12.30%