Summary of Potential Number of Units that Could Vest Under Restricted Stock Unit Awards (Parenthetical) (Detail) - $ / shares |
12 Months Ended | ||
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Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
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| Restricted Stock Units (RSUs) | |||
| Schedule of Restricted Stock Unit [Line Items] | |||
| Weighted average market value on grant dates | $ 29.83 | $ 43.19 | $ 28.54 |
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- Definition Schedule of Restricted Stock Unit [Line Items] No definition available.
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- Definition The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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