Leases, Codification Topic 842 (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Lessee, Lease, Description [Line Items]
Operating Lease, Expense	$ 87	$ 70
Variable Lease, Cost	21	37
Short-term Lease, Cost	2	14
Operating Lease, Cost	110	121
Operating Lease, Payments	85	69
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 90	$ 52
Operating Lease, Weighted Average Remaining Lease Term	7 years 2 months 12 days	4 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent	2.70%	3.20%
Operating Lease, Right-of-Use Asset	$ 242	$ 193
Operating Lease, Liability, Current	76	69
Operating Lease, Liability, Noncurrent	202	155
Operating Lease, Liability	278	$ 224
Lessee, Operating Lease, Liability, Payments, Due Year Two	72
Lessee, Operating Lease, Liability, Payments, Due Year Three	42
Lessee, Operating Lease, Liability, Payments, Due Year Four	34
Lessee, Operating Lease, Liability, Payments, Due Year Five	27
Lessee, Operating Lease, Liability, Payments, Due	308
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(30)
Operating Leases, Future Minimum Payments Due, Next Twelve Months	56
Operating Leases, Future Minimum Payments, Due Thereafter	77
Unrecorded unconditional purchase obligation	$ 3,922
Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract	12 years
Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract	3 years
Operating Lease [Member]
Lessee, Lease, Description [Line Items]
Unrecorded unconditional purchase obligation	$ 163