Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Plans - Amendments to Restricted Stock and SARs - Additional Information (Detail)

v3.3.1.900
Stock-Based Compensation Plans - Amendments to Restricted Stock and SARs - Additional Information (Detail) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2013
Dec. 31, 2015
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock-based compensation charges $ 30,900   $ 30,886
Deferred stock units [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
DSU settlement to common stock percentage   20.00%  
DSU settlement into actual stock issued term   5 years  
Employee termination age   67 years  
Percentage of shares of deferred stock units released from resale restriction in the event of death or termination after reaching age 67   100.00%  
Restricted Stock Awards [Member] | Sales Restricted [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Sales restriction lapse percentage for restricted stock   20.00%  
Sales restriction period for restricted stock   5 years  
Employee termination age   67 years  
Percentage of shares of stock released from resale restriction upon consummation of change of control   100.00%  
Percentage of shares of restricted released from resale restriction in the event of death or termination after reaching age 67   100.00%