Leases - Component of Lease Cost and Consolidated Balance Sheet Amounts (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2020
Leases [Abstract]
Operating lease cost	$ 547	$ 569	$ 1,599	$ 1,489
Short-term lease cost	50	63	251	318
Variable lease cost	241	97	532	304
Total lease cost	838	$ 729	2,382	$ 2,111
Operating leases
Operating lease right-of-use assets	7,895		7,895		$ 8,116
Operating lease liabilities	$ 8,533		$ 8,533		$ 8,647
Weighted-average remaining lease term
Operating leases	13 years 10 months		13 years 10 months		14 years 4 months
Weighted-average discount rate
Operating leases	4.30%		4.30%		4.50%