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Summary of Significant Accounting Policies (Tables) | 12 Months Ended
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Mar. 31, 2021
Accounting Policies [Abstract] |
Property, Plant and Equipment Estimated Useful Lives | Depreciation of property, plant and equipment is computed using the straight-line method over the following estimated useful lives:
| Years
Buildings | 5 to 50
Buildings Improvements | 1 to 40
Leasehold Improvements | 1 to 40
Machinery and Equipment | 1 to 30
Basic and Dilutive Common Shares Outstanding Used in Determining Net Income Per Share | Basic and dilutive common shares outstanding used in determining net income per share are as follows:
| Years Ended 31 March
(Millions of shares) | 2021 |  | 2020 |  | 2019
Basic common shares outstanding | 443.7 |  |  | 442.6 |  |  | 441.9 |
Dilutive effect of stock awards | 1.7 |  |  | 1.5 |  |  | 1.1 |
Diluted common shares outstanding | 445.4 |  |  | 444.1 |  |  | 443.0 |

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- Definition Tabular disclosure of the weighted average number of shares used in calculating basic net earnings per share (or unit) and diluted earnings per share (or unit). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
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