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Quarterly Financial Data (Unaudited) (Details) (USD $)
In Millions, except Per Share data |
3 Months Ended | 12 Months Ended | |||||||||
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May 31, 2011
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Feb. 28, 2011
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Nov. 30, 2010
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Aug. 31, 2010
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May 31, 2010
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Feb. 28, 2010
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Nov. 30, 2009
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Aug. 31, 2009
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May 31, 2011
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May 31, 2010
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May 31, 2009
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| Selected Quarterly Financial Information [Abstract] | |||||||||||
| Service revenue | $ 510.4 | $ 519.6 | $ 500.0 | $ 506.2 | $ 482.5 | $ 493.8 | $ 483.0 | $ 486.5 | $ 2,036.2 | $ 1,945.8 | $ 2,007.3 |
| Interest on funds held for clients | 12.3 | 11.7 | 12.0 | 12.1 | 13.7 | 14.0 | 13.6 | 13.7 | 48.1 | 55.0 | 75.5 |
| Total revenue | 522.7 | 531.3 | 512.0 | 518.3 | 496.2 | 507.8 | 496.6 | 500.2 | 2,084.3 | 2,000.8 | 2,082.8 |
| Operating income | 182.8 | 198.9 | 203.9 | 200.8 | 173.6 | 168.2 | 193.1 | 189.9 | 786.4 | 724.8 | 805.2 |
| Investment income, net | 1.4 | 1.5 | 1.5 | 1.4 | 1.3 | 1.2 | 1.1 | 0.9 | 5.8 | 4.5 | 6.9 |
| Income before income taxes | 184.2 | 200.4 | 205.4 | 202.2 | 174.9 | 169.4 | 194.2 | 190.8 | 792.2 | 729.3 | 812.1 |
| Income taxes | 65.3 | 69.8 | 71.5 | 70.3 | 59.4 | 57.4 | 68.3 | 67.2 | 276.9 | 252.3 | 278.6 |
| Net income | 118.9 | 130.6 | 133.9 | 131.9 | 115.5 | 112.0 | 125.9 | 123.6 | 515.3 | 477.0 | 533.5 |
| Basic earnings per share | $ 0.33 | $ 0.36 | $ 0.37 | $ 0.36 | $ 0.32 | $ 0.31 | $ 0.35 | $ 0.34 | $ 1.42 | $ 1.32 | $ 1.48 |
| Diluted earnings per share | $ 0.33 | $ 0.36 | $ 0.37 | $ 0.36 | $ 0.32 | $ 0.31 | $ 0.35 | $ 0.34 | $ 1.42 | $ 1.32 | $ 1.48 |
| Weighted-average common shares outstanding | 362.0 | 361.8 | 361.7 | 361.6 | 361.5 | 361.4 | 361.4 | 361.2 | 361.8 | 361.4 | 360.8 |
| Weighted-average common shares outstanding, assuming dilution | 363.0 | 362.6 | 362.1 | 362.0 | 362.0 | 361.9 | 361.7 | 361.4 | 362.4 | 361.7 | 361.0 |
| Cash dividends per common share | $ 0.31 | $ 0.31 | $ 0.31 | $ 0.31 | $ 0.31 | $ 0.31 | $ 0.31 | $ 0.31 | $ 1.24 | $ 1.24 | $ 1.24 |
| Total net realized gains | 0.9 | 0.1 | 0.2 | 0.1 | 0.9 | 1.3 | 0.7 | 0.3 | 1.3 | 3.2 | 1.1 |
| Quarterly Financial Data (Textuals) [Abstract] | |||||||||||
| Increase in litigation reserve | $ 18.7 | $ 18.7 | |||||||||
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- Definition
Increase in litigation reserve.
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Interest on funds held for clients.
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- Definition
Quarterly Financial Data.
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- Definition
Aggregate dividends paid during the period for each share of common stock outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The amount of net income or loss for the period per each share of common stock outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The amount of net income or loss for the period per each share of common stock and dilutive common stock equivalents outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The net realized gain or loss on investments sold during the period, which, for cash flow reporting, is a component of proceeds from investing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Sum of operating profit and nonoperating income (expense) before income (loss) from equity method investments, income taxes, extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The sum of the current income tax expense (benefit) and the deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The aggregate amount of income from investments (for example, dividends) not considered a component of the entity's core operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The portion of consolidated profit or loss for the period, net of income taxes, which is attributable to the parent. If the entity does not present consolidated financial statements, the amount of profit or loss for the period, net of income taxes. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The net result for the period of deducting operating expenses from operating revenues.
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- Definition
Aggregate revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Aggregate revenue during the period from services rendered in the normal course of business, after deducting allowances and discounts. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
The average number of shares issued and outstanding that are used in calculating diluted EPS, determined based on the timing of issuance of shares in the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Number of [basic] shares, after adjustment for contingently issuable shares and other shares not deemed outstanding, determined by relating the portion of time within a reporting period that common shares have been outstanding to the total time in that period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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