Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Lease costs:
Operating lease costs	$ 2,888
Variable operating lease costs	77
Total lease costs	2,965
Operating cash flows for operating leases	2,003	$ 0
Right-of-use assets obtained in exchange for lease obligations	$ 51,597
Weighted-average remaining lease term (years) of operating leases	7 years 1 month 16 days
Weighted-average discount rate of operating leases	5.77%