XML 25 R104.htm IDEA: XBRL DOCUMENT v2.4.0.8
Equity-Based Compensation - Weighted-Average Assumptions Used for Employee Purchase Rights Granted Under Stock Purchase Plan (Detail) (USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected dividend yield 0.00% 0.00% 0.00%
Stock Purchase Plan [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Fair market value $ 42.45 $ 35.43 $ 34.77
Option price $ 40.33 $ 33.66 $ 33.03
Expected dividend yield 0.00% 0.00% 0.00%
Expected volatility 19.00% 21.00% 33.00%
Risk free interest rate 0.05% 0.07% 0.07%