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Accounting for Stock-Based Compensation (Tables) | 6 Months Ended
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Nov. 30, 2011
Accounting for Stock-Based Compensation |
Assumptions used in the Black-Scholes option pricing model to estimate the fair value of each stock option grant |
|  | Six Months Ended |
|  | November 30, |
|  | 2011 |  | 2010 |
Risk-free interest rate |  | 1.5 | % | 1.8 | %
Expected volatility of common stock |  | 45.8 | % | 47.0 | %
Dividend yield |  | 1.0 | % | 0.0 | %
Expected option term in years |  | 5.7 |  | 5.8 |
Summary of stock option activity |
|  |  |  |  |  | Weighted |  |  |
|  |  |  | Weighted |  | Average |  |  |
|  | Number of |  | Average |  | Remaining |  | Aggregate |
|  | Options |  | Exercise |  | Contractual |  | Intrinsic |
|  | (in thousands) |  | Price |  | Life (years) |  | Value |
Outstanding at May 31, 2011 |  | 1,994 |  | $ | 18.56 |  |  |  |  |
Granted |  | 162 |  | $ | 28.96 |  |  |  |  |
Exercised |  | (332 | ) | $ | 20.03 |  |  |  |  |
Cancelled |  | (45 | ) | $ | 17.81 |  |  |  |  |
Outstanding at November 30, 2011 |  | 1,779 |  | $ | 19.65 |  | 6.5 |  | $ | 3,408 |
Exercisable at November 30, 2011 |  | 871 |  | $ | 18.27 |  | 4.2 |  | $ | 2,301 |
Schedule of restricted share activity |
|  | Number of |  | Weighted Average |
|  | Shares |  | Fair Value |
|  | (in thousands) |  | on Grant Date |
Unvested at May 31, 2011 |  | 1,374 |  | $ | 23.06 |
Granted |  | 672 |  | $ | 24.61 |
Vested |  | (324 | ) | $ | 26.71 |
Forfeited |  | (84 | ) | $ | 24.01 |
Unvested at November 30, 2011 |  | 1,638 |  | $ | 22.91 |

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- Definition Tabular disclosure of the changes in outstanding nonvested shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Topic 718 -SubTopic 10 -Publisher FASB -Number -Article -Subparagraph (c)(2) -Name Accounting Standards Codification -Paragraph 2 -Section 50 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Tabular disclosure of the number and weighted-average exercise prices (or conversion ratios) for share options (or share units) that were outstanding at the beginning and end of the year, vested and expected to vest, exercisable or convertible at the end of the year, and the number of share options or share units that were granted, exercised or converted, forfeited, and expired during the year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Topic 718 -SubTopic 10 -Publisher FASB -Number -Article -Subparagraph (c)(1) -Name Accounting Standards Codification -Paragraph 2 -Section 50 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Topic 718 -SubTopic 10 -Publisher FASB -Number -Article -Subparagraph (f)(2) -Name Accounting Standards Codification -Paragraph 2 -Section 50 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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