XML 40 R67.htm IDEA: XBRL DOCUMENT v3.3.0.814
Employee Benefit Plans - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Percentage of employees contributions maximum 50.00%    
Percentage of company matches of employees contributions maximum 3.00%    
Employee vesting period Two years of service    
Employer contributions for benefit plans $ 36 $ 28 $ 22