Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Leases, Supplemental Cash Flow Information [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities – operating cash flows	$ 371	$ 463
ROU assets obtained in exchange for lease, net	130	449
Change in lease classification from operating to finance lease	792	529
Finance Leases, Supplemental Cash Flow Information [Abstract]
Interest paid for finance lease liabilities – Operating cash flows	22	35
Cash paid for amounts included in the measurement of finance lease obligations – financing cash flows	403	430
Total cash paid in the measurement of finance lease obligations	425	465
Capital expenditures through finance lease obligations	$ 180	$ 277