Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Mar. 31, 2020	Mar. 31, 2019
Assets
Finance lease assets, gross	$ 395	$ 377
Accumulated depreciation	(168)	(130)
Finance lease assets, net	227	247
Operating lease assets	157	0
Total lease assets	384	247
Current
Current finance lease obligations	111	137
Current operating lease obligations	39	0
Non-current
Non-current finance lease obligations	136	168
Total lease liabilities	415	305
Other long-term liabilities
Non-current
Operating leases	$ 129	$ 0