Leases - Component of Lease Cost and Consolidated Balance Sheet Amounts (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2020
Leases [Abstract]
Operating lease cost	$ 481	$ 514	$ 1,052	$ 920
Short-term lease cost	139	50	201	255
Variable lease cost	216	71	291	207
Sublease income	0	0	0	0
Total lease cost	836	$ 635	1,544	$ 1,382
Operating leases
Operating lease right-of-use assets	8,097		8,097		$ 8,116
Operating lease liabilities	$ 8,722		$ 8,722		$ 8,647
Weighted-average remaining lease term
Operating leases	13 years 9 months		13 years 9 months		14 years 4 months
Weighted-average discount rate
Operating leases	4.40%		4.40%		4.50%