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Stock-Based Compensation Plans - Amendments to Restricted Stock and SARs - Additional Information (Detail) - Deferred stock units [Member] | Nov. 05, 2013
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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 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

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