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Accounting for Stock-Based Compensation (Tables)
3 Months Ended
Aug. 31, 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

 

 

 

Three Months Ended

 

 

 

August 31,

 

 

 

2011

 

2010

 

Risk-free interest rate

 

1.5

%

1.9

%

Expected volatility of common stock

 

45.7

%

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

 

157

 

$

29.30

 

 

 

 

 

Exercised

 

(332

)

$

20.03

 

 

 

 

 

Cancelled

 

(31

)

$

17.11

 

 

 

 

 

Outstanding at August 31, 2011

 

1,788

 

$

19.66

 

6.9

 

$

11,362

 

Exercisable at August 31, 2011

 

866

 

$

18.28

 

4.4

 

$

6,427

 

 

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

 

598

 

$

23.99

 

Vested

 

(324

)

$

26.71

 

Forfeited

 

(49

)

$

24.54

 

Unvested at August 31, 2011

 

1,599

 

$

22.61