Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Details)

v2.4.0.6
Stock-Based Compensation (Details) (USD $)
3 Months Ended
Mar. 31, 2012
Stock-Based Compensation Arrangement By Stock-Based Payment Award [Line Items]  
Options granted in period 855,058
Exercise price of options granted $ 145.58
Vesting period 3 years
Expected volatility, minimum 27.00%
Expected volatility, maximum 31.00%
Weighted average, expected volatility 30.00%
Expected term (in years), minimum 5.6
Expected term (in years), maximum 7.5
Expected dividend yield 2.50%
Ten years risk-free interest rate 2.10%
Six months risk-free interest rate 0.10%
Weighted average fair value of options granted $ 33.43
Performance based adjustment 25.00%
Performance based period 3 years
Restricted Stock Units [Member]
 
Stock-Based Compensation Arrangement By Stock-Based Payment Award [Line Items]  
Fair value of restricted stock units at the grant date $ 145.58
Restricted Stock [Member]
 
Stock-Based Compensation Arrangement By Stock-Based Payment Award [Line Items]  
Restricted stock units granted in period 5,500
Fair value of restricted stock units at the grant date $ 141.77
Performance-Based [Member] | Restricted Stock Units [Member]
 
Stock-Based Compensation Arrangement By Stock-Based Payment Award [Line Items]  
Vesting period 3 years
Restricted stock units granted in period 191,788
Nonperformance Based [Member] | Restricted Stock Units [Member]
 
Stock-Based Compensation Arrangement By Stock-Based Payment Award [Line Items]  
Restricted stock units granted in period 4,345
Minimum [Member]
 
Stock-Based Compensation Arrangement By Stock-Based Payment Award [Line Items]  
Performance based adjustment 0.00%
Minimum [Member] | Performance-Based [Member] | Restricted Stock Units [Member]
 
Stock-Based Compensation Arrangement By Stock-Based Payment Award [Line Items]  
Range of possible awards 0.00%
Maximum [Member] | Performance-Based [Member] | Restricted Stock Units [Member]
 
Stock-Based Compensation Arrangement By Stock-Based Payment Award [Line Items]  
Range of possible awards 200.00%