v3.5.0.2
Equity (Tables)
9 Months Ended
Sep. 30, 2016
Equity [Abstract]  
Summary of Stock Options
The following is a summary of stock options for the nine months ended September 30, 2016:
 
Number of Options
 
Weighted Average
Exercise Price per
Option
Outstanding at December 31, 2015
774,551

 
$
159.66

Granted
150,323

 
250.07

Exercised
(135,048
)
 
146.26

Outstanding at September 30, 2016
789,826

 
179.16

Details of Stock Options Outstanding
Details of stock options outstanding as of September 30, 2016 are as follows:
 
Number of Options
 
Weighted Average
Exercise Price
 
Weighted Average
Remaining
Contractual Life
(Years)
 
Aggregate
Intrinsic
Value
(In millions)
Vested or expected to vest
789,826

 
$
179.16

 
6.8
 
$
71

Exercisable
544,367

 
$
154.58

 
5.9
 
$
62

Stock Options Valuation Assumptions
During the nine months ended September 30, 2016 and 2015, we used the weighted-average assumptions in the table below to compute the value of all options for shares of common stock granted to employees:
 
Nine Months Ended September 30,
Assumptions:
2016
 
2015
Risk-free interest rate
1.51
%
 
1.08
%
Expected life in years
5.0

 
5.0

Expected volatility
24
%
 
24
%
Expected dividend yield
1.36
%
 
1.25
%
Estimated weighted-average fair value of options granted per share
$
49.39

 
$
40.94

Summary of Nonvested Restricted Stock Options
The following is a summary of the non-vested restricted shares for the nine months ended September 30, 2016:  
 
Number of
Restricted
Stock Shares
 
Weighted Average
Grant-Date Fair
Value per Share
Non-vested at December 31, 2015
1,254,235
 
$
199.44

Granted
614,479
 
249.43

Vested
(476,581)
 
188.73

Forfeited
(66,266)
 
227.27

Non-vested at September 30, 2016
1,325,867
 
225.54