Right-of-Use Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Assets
Operating lease right-of-use-assets	$ 13,044
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Operating lease right-of-use-assets
Liabilities
Operating lease liabilities (short-term)	$ 1,935
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued Liabilities, Current
Operating lease liabilities (long-term)	$ 11,995
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Operating lease liabilities (long-term)
Total lease liabilities	$ 13,930
Lease Costs
Lease costs	2,600	$ 1,900	$ 1,800
Variable lease costs	$ 0	$ 0	$ 0
Minimum
Operating Lease
Renewal option term	1 year	1 year	1 year
Maximum
Operating Lease
Renewal option term	5 years	5 years	5 years