XML 38 R16.htm IDEA: XBRL DOCUMENT v2.4.0.8
Share-Based Compensation (Tables)
 9 Months Ended
Sep. 30, 2013
Share-based Compensation [Abstract]  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Method Used
The fair value of each option grant is estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions:
 
 
 
 
 
Nine months ended September 30,
 
2013
 
2012
Dividend yield
1.50 - 1.53%

 
1.30 - 1.35%

Volatility - stock option plans
38
%
 
38 - 39%

Volatility - stock purchase rights plans
21
%
 
34
%
Risk free interest rates
.12 - 1.40%

 
.19 - 1.43%

Expected life (years) - stock option plans
5.91 - 7.43

 
5.79 - 7.26

Expected life (years) - stock purchase rights plans
1

 
1

Weighted average fair value of stock options granted during the period
$
11.17

 
$
13.53

Weighted average fair value of stock purchase rights granted during the period
$
9.43

 
$
9.70
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Total stock compensation expense and the total related tax benefit recognized are as follows:
 
Three months ended
 
Nine months ended
 
September 30,
 
September 30,
 
2013
 
2012
 
2013
 
2012
Stock compensation expense
$
11,015

 
$
11,320

 
$
33,060

 
$
32,846

Recognized tax benefit
$
943

 
$
996

 
$
2,492

 
$
1,371