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Share-Based Compensation - Weighted-Average Estimated Fair Value Per Share of Options Granted under Plans (Detail) (USD $)
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12 Months Ended | ||
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Dec. 31, 2012
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Dec. 31, 2011
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Dec. 31, 2010
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Weighted-Average Estimated Fair Value Per Share of Options Granted | $ 5.40 | $ 6.23 | |
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- Details
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- Definition
The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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