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           Share-Based Compensation (Tables) 
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        3 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
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           Mar. 31, 2014 
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| Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Share-Based Compensation Expense is Classified in Condensed Consolidated Statements of Comprehensive Loss | 
 Share-based compensation expense is classified in the condensed consolidated statements of comprehensive loss as follows: 
 
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