Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Lease costs:
Operating lease costs	$ 2,848	$ 8,601
Variable operating lease costs	79	233
Total lease costs	2,927	8,834
Operating cash flows for operating leases	1,949	6,013	$ 0
Right-of-use assets obtained in exchange for lease obligations	$ 629	$ 52,226
Weighted-average remaining lease term (years) of operating leases	6 years 9 months 18 days	6 years 9 months 18 days
Weighted-average discount rate of operating leases	5.80%	5.80%