| Schedule of Options Assigned (Details) (USD $) | Dec. 31, 2012 | 
|---|---|
| Unexercised Options | 3,711,937 | 
| Manager2Member | |
| Date of Grant/Exercise | 2003 | 
| Strike Price, lower range | 20.35 | 
| Strike price, upper range | 22.85 | 
| Unexercised Options | 164,197 | 
| Manager3Member | |
| Date of Grant/Exercise | 2004 | 
| Strike Price, lower range | 25.75 | 
| Strike price, upper range | 31.40 | 
| Unexercised Options | 226,125 | 
| Manager4Member | |
| Date of Grant/Exercise | 2005 | 
| Range of strike prices | 29.60 | 
| Unexercised Options | 89,925 | 
| Manager5Member | |
| Date of Grant/Exercise | 2006 | 
| Range of strike prices | 29.42 | 
| Unexercised Options | 48,875 | 
| Manager6Member | |
| Date of Grant/Exercise | 2007 | 
| Strike Price, lower range | 27.75 | 
| Strike price, upper range | 31.30 | 
| Unexercised Options | 172,815 | 
| Manager12Member | |
| Date of Grant/Exercise | 2011 | 
| Strike Price, lower range | 4.55 | 
| Strike price, upper range | 6.00 | 
| Unexercised Options | 1,460,000 | 
| Manager13Member | |
| Date of Grant/Exercise | 2012 | 
| Strike Price, lower range | 6.22 | 
| Strike price, upper range | 6.71 | 
| Unexercised Options | 1,550,000 | 
| X | ||||||||||
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- Definition The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range. No definition available. 
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| X | ||||||||||
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- Definition The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range. No definition available. 
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- Definition The date of grant/exercise of stock options, as depicted in the schedule of stock option activity. No definition available. 
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- Definition The number of unexercised options from inception to date. No definition available. 
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- Definition Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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