Leases, Codification Topic 842 (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2020	Apr. 01, 2019	Mar. 31, 2019
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Remaining Lease Term	15 years
Operating Lease, Expense	$ 70
Variable Lease, Cost	37
Short-term Lease, Cost	14
Operating Lease, Cost	121
Operating Lease, Payments	69
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 52
Operating Lease, Weighted Average Remaining Lease Term	4 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent	3.20%
Operating Lease, Right-of-Use Asset	$ 193	$ 215
Operating Lease, Liability, Current	69	50	$ 0
Operating Lease, Liability, Noncurrent	155	197
Operating Lease, Liability	224	$ 247
Lessee, Operating Lease, Liability, Payments, Due Year Two	74
Lessee, Operating Lease, Liability, Payments, Due Year Three	58
Lessee, Operating Lease, Liability, Payments, Due Year Four	33
Lessee, Operating Lease, Liability, Payments, Due Year Five	28
Lessee, Operating Lease, Liability, Payments, Due Year Six	21
Lessee, Operating Lease, Liability, Payments, Due After Year Six	28
Lessee, Operating Lease, Liability, Payments, Due	242
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(18)
Operating Leases, Future Minimum Payments Due, Next Twelve Months			52
Operating Leases, Future Minimum Payments, Due in Two Years			54
Operating Leases, Future Minimum Payments, Due in Three Years			44
Operating Leases, Future Minimum Payments, Due in Four Years			36
Operating Leases, Future Minimum Payments, Due in Five Years			28
Operating Leases, Future Minimum Payments, Due Thereafter			50
Operating Leases, Future Minimum Payments Due			$ 264
Unrecorded unconditional purchase obligation	$ 1,373
Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract	15 years
Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract	12 years
Operating Lease [Member]
Lessee, Lease, Description [Line Items]
Unrecorded unconditional purchase obligation	$ 169