XML 135 R106.htm IDEA: XBRL DOCUMENT v3.3.1.900
Stock-Based Compensation - Additional Information (Detail)
 12 Months Ended
Dec. 31, 2015
Incentive_Stock_Option_Plan
shares
Dec. 31, 2014
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of incentive stock option plans | Incentive_Stock_Option_Plan 2  
Holding period of restricted stock available to executives 4 years  
Share based compensation arrangement long-term retention program restricted stock available to executive releasing period 10 years  
Number of days considered for weighted average trading price 20 days  
Percentage of annual retainers 60.00%  
Percentage of additional annual retainers 100.00%  
Stock Option Plan 1987 [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Period of granted option 7 years  
Stock Option Plan 2009 [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Maximum number of shares, issued under the option plan 32,000,000  
Number of shares available to be granted 12,164,270 13,586,060
Period of granted option 7 years  
Option vested under stock option plan to employees, consultants and most senior executives One-third on each of the first three anniversaries of the date of grant.  
Performance-Vested Options [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Option vested under stock option plan to employees, consultants and most senior executives one-sixth, one-third and one-half on the first three anniversaries of the date of grant, subject to satisfaction of a minimum total shareholder return condition