| Stock-Based Compensation (Narrative) (Details) (USD $) | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011 | |
| Share-based Compensation [Abstract] | |||
| Stock options issued | 0 | 0 | 0 | 
| Stock-based compensation expense | $ 10,500,000 | $ 4,700,000 | $ 1,300,000 | 
| Capitalized stock-based compensation | 4,198,000 | 1,875,000 | 515,000 | 
| Unrecognized compensation expense | $ 19,200,000 | ||
| Weighted average period | 1 year 7 months 24 days | ||
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- Definition Non-cash stock based compensation capitalized. No definition available. 
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- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Unrecognized cost of unvested share-based compensation awards. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
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- Definition Net number of share options (or share units) granted during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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