Leases - Supplemental balance sheet information (Details) - USD ($) $ in Millions	Mar. 31, 2022	Mar. 31, 2021	Apr. 01, 2019
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	$ 1,548	$ 2,100	$ 2,100
Current portion of operating lease liabilities	297	390
Long-term operating lease liabilities	1,366	1,867
Total operating lease liabilities	$ 1,663	$ 2,257	$ 2,200
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, plant, and equipment, net	Property, plant, and equipment, net
Property, plant and equipment, net	$ 206	$ 237
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Less: Current portion	Less: Current portion
Current portion of long-term debt	$ 25	$ 22
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Long-term debt	Long-term debt
Long-term debt	$ 185	$ 206
Total finance lease liabilities	$ 210	$ 228
Weighted average remaining lease term (Years) - Operating leases	6 years 10 months 24 days	7 years 9 months 18 days
Weighted average remaining lease term (Years) - Finance leases	8 years 9 months 18 days	10 years 1 month 6 days
Weighted average discount rate - Operating leases (percent)	2.47%	2.53%
Weighted average discount rate - Finance leases (percent)	2.50%	2.71%
European Businesses (Disposal Group) | Held-for-sale
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	$ 494
Current portion of operating lease liabilities	83
Long-term operating lease liabilities	$ 442