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Share-Based Compensation - Additional Information (Detail) $ in Millions | 12 Months Ended
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Dec. 31, 2015 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Unrecognized compensation cost related to all nonvested awards | $ 22.6
Unrecognized compensation cost is expected to be recognized over a weighted-average period | 1 year 9 months 18 days
SARs and Stock Options [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
SAR's and stock options expiration period | 10 years
Restricted Shares and Units [Member] | Minimum [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting period | 3 years
Restricted Shares and Units [Member] | Maximum [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting period | 5 years
Market Based Restricted Stock Units [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting period | 3 years
Performance Conditions One Member [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Percentage of restricted stock units issued on second anniversary | 50.00%
Percentage of restricted stock units issued on third anniversary | 50.00%
Performance Conditions Two Member [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Percentage of restricted stock units issued on third anniversary | 100.00%

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