Quarterly report pursuant to Section 13 or 15(d)

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

v3.20.2
Stock-Based Compensation Plans - Amendments to Restricted Stock and SARs - Additional Information (Detail) - Deferred stock units [Member]
Oct. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
DSU settlement to common stock percentage 20.00%
Employee termination age 67 years
Percentage of shares of deferred stock units settled in the event of death or termination after reaching age 67 100.00%
Share-based compensation arrangement by share-based payment award, stock appreciation rights, offering date Mar. 31, 2013