Leases - Supplemental Statement of Operations Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Finance lease expense:
Net lease expense	$ 1,290	$ 2,633
Marketing, general and administrative and engineering
Lessee, Lease, Description [Line Items]
Operating lease expense	959	1,767
Finance lease expense:
Amortization of ROU assets	66	125
Short-term lease expense	252	715
Interest expense
Finance lease expense:
Interest expense on finance lease liabilities	$ 13	$ 26