Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Assets
Finance lease assets	$ 260,000
Finance lease assets, accumulated depreciation	120
Operating lease assets	92,000
Liabilities	352,000
Current
Finance leases	119,000	$ 137,000
Operating leases	40,000
Non-current
Finance leases	164,000
Operating leases	70,000
Total lease liabilities	$ 393,000