Share-based Compensation (Tables)
 3 Months Ended
Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Key Assumptions Used to Estimate Fair Value of Stock Options Granted

The following are the key assumptions used for options granted during the three month periods ended March 31:

 

     2015   2014  

Risk-free interest rate

    1.3% - 1.5%     1.5 % 

Expected life of the options (years)

    5     5   

Expected stock price volatility

    35.6% - 35.7%     38.4 % 

Expected dividend rate

    1.8% - 2.0%     1.6 % 
Stock Option Activity

The following table summarizes stock option activity for the three months ended March 31, 2015 (share amounts in thousands):

 

     Number of
Shares		      Weighted
Average
Exercise Price		  

Options outstanding, beginning of period

      2,649       $ 32.33   

Granted

      363         42.80   

Canceled/Expired

      (16 )       45.72   

Exercised

      (1 )       25.43   
  

 

 

     

Options outstanding, end of period

   2,995      33.53   
  

 

 

     
Fully Vested Stock Options and Stock Options Expected to Vest

A summary of stock options outstanding as of March 31, 2015, is as follows:

 

     Number of
Shares		      Weighted
Average
Exercise
Price		      Weighted
Average
Remaining
Contractual
Terms		      Aggregate
Intrinsic
Value		  
     (In thousands)             (In years)      (In thousands)  

Outstanding

      2,995       $ 33.53         8.11       $ 28,595   

Vested and expected to vest

      2,887         33.28         8.07         28,242   

Exercisable

      1,659         30.80         7.68         19,997   
Nonvested Share-Awards Activity

A summary of nonvested share-awards activity is as follows (share amounts in thousands):

 

     Shares      Weighted Average
Grant Date Fair
Value		  

Nonvested at beginning of period

      343       $ 27.99   

Awarded

      81         37.22   

Released

      (29 )       34.78   

Forfeited

      (11 )       24.14   
  

 

 

     

Nonvested at end of period

   384      29.57