XML 62 R41.htm IDEA: XBRL DOCUMENT v2.4.0.8
Stock-Based Compensation (Detail) - (Table 4) (USD $)
3 Months Ended
Mar. 31, 2014
Mar. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Dividend yield 0.00% 0.00%
Weighted average fair value $ 10.04 $ 9.91
Minimum [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Volatility 29.70% 38.20%
Risk free interest rate 1.06% 0.37%
Expected life in years 4 years 1 month 4 years 1 month
Maximum [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Volatility 31.80% 44.80%
Risk free interest rate 1.72% 0.76%
Expected life in years 5 years 1 month 5 years 1 month