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Summary of Significant Accounting Policies (Tables) | 12 Months Ended
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Mar. 31, 2017
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 |  |  | 10 to 40 |
Buildings Improvements |  |  | 3 to 25 |
Leasehold Improvements |  |  | 5 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) |  | 2017 |  |  | 2016 |  |  | 2015 |
Basic common shares outstanding |  |  | 442.7 |  |  |  | 445.3 |  |  |  | 445.0 |
Dilutive effect of stock awards |  |  | 1.2 |  |  |  | 1.9 |  |  |  | 1.4 |
Diluted common shares outstanding |  |  | 443.9 |  |  |  | 447.2 |  |  |  | 446.4 |
(US dollars) |  | 2017 |  |  | 2016 |  |  | 2015 |
Net income per share - basic |  |  | 0.62 |  |  |  | 0.55 |  |  |  | 0.65 |
Net income per share - diluted |  |  | 0.62 |  |  |  | 0.55 |  |  |  | 0.65 |

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- Definition Tabular disclosure of an entity's basic and diluted earnings per share calculations, including a reconciliation of numerators and denominators of the basic and diluted per-share computations for income from continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -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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