v2.4.0.8
Long-Term Compensation - RSU and Performance Share Awards (Parenthetical) (Detail) (Restricted Stock Units (RSUs) [Member])
9 Months Ended
Sep. 30, 2014
Restricted Stock Units (RSUs) [Member]
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Vesting period 3 years