Description of Business, Basis of Presentation, and Significant Accounting Policies (Schedule of Recast of Selected Unaudited Consolidated Statements of Income and Comprehensive Income) (Details) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | 6 Months Ended | ||||||||
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Nov. 30, 2018 |
Nov. 30, 2017 |
Nov. 30, 2018 |
Nov. 30, 2017 |
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| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||||||||||
| Service revenue | $ 840.6 | $ 789.0 | [1] | $ 1,686.3 | $ 1,568.2 | [1] | ||||
| Operating expenses | 264.9 | 248.6 | [1] | 530.4 | 480.6 | [1] | ||||
| Selling, general and administrative expenses | 286.8 | 251.3 | [1] | 563.8 | 494.9 | [1] | ||||
| Total expenses | 551.7 | 499.9 | [1] | 1,094.2 | 975.5 | [1] | ||||
| Operating income | 307.2 | 303.1 | [1] | 627.5 | 620.4 | [1] | ||||
| Income taxes | 73.5 | 106.0 | [1] | 152.5 | 215.0 | [1] | ||||
| Net income | $ 235.8 | $ 198.8 | [1],[2] | $ 479.4 | $ 409.2 | [1],[2] | ||||
| Basic earnings per share | $ 0.66 | $ 0.55 | [1],[2] | $ 1.34 | $ 1.14 | [1],[2] | ||||
| Diluted earnings per share | $ 0.65 | $ 0.55 | [1],[2] | $ 1.33 | $ 1.13 | [1],[2] | ||||
| As Previously Reported [Member] | ASU 2014-09 [Member] | ||||||||||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||||||||||
| Service revenue | $ 812.5 | $ 1,615.6 | ||||||||
| Operating expenses | 248.7 | 480.8 | ||||||||
| Selling, general and administrative expenses | 245.6 | 485.3 | ||||||||
| Total expenses | 494.3 | 966.1 | ||||||||
| Operating income | 332.2 | 677.2 | ||||||||
| Income taxes | 116.9 | 236.2 | ||||||||
| Net income | $ 217.0 | $ 444.8 | ||||||||
| Basic earnings per share | $ 0.60 | $ 1.24 | ||||||||
| Diluted earnings per share | $ 0.60 | $ 1.23 | ||||||||
| Adjustments [Member] | ASU 2014-09 [Member] | ||||||||||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||||||||||
| Service revenue | $ (23.5) | $ (47.4) | ||||||||
| Operating expenses | (0.1) | (0.2) | ||||||||
| Selling, general and administrative expenses | 5.7 | 9.6 | ||||||||
| Total expenses | 5.6 | 9.4 | ||||||||
| Operating income | (29.1) | (56.8) | ||||||||
| Income taxes | (10.9) | (21.2) | ||||||||
| Net income | $ (18.2) | $ (35.6) | ||||||||
| Basic earnings per share | $ (0.05) | $ (0.10) | ||||||||
| Diluted earnings per share | $ (0.05) | $ (0.10) | ||||||||
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- Definition The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Excludes Selling, General and Administrative Expense. No definition available.
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- Definition Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense. No definition available.
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- Definition The net result for the period of deducting operating expenses from operating revenues. No definition available.
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- Definition Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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