Stock-Based Compensation (Details 1) (Restricted Stock Units (RSUs) [Member], USD $)	Dec. 31, 2012
Restricted Stock Units (RSUs) [Member]
Expense recognition of deferred compensation
2013	$ 4,666,887
2014	4,349,048
2015	3,444,556
2016	1,605,186
2017	763,793
Total	$ 14,829,470

Employee service share based compensation nonvested awards compensation cost not yet recognized in year five.

No definition available.

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- Definition

Employee service share based compensation nonvested awards compensation cost not yet recognized in year four

+ References

No definition available.

+ Details

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- Definition

Employee service share based compensation nonvested awards compensation cost not yet recognized in year one.

+ References

No definition available.

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- Definition

Employee service share based compensation nonvested awards compensation cost not yet recognized in year three.

+ References

No definition available.

+ Details

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- Definition

Employee service share based compensation nonvested awards compensation cost not yet recognized in year two.

+ References

No definition available.

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- Definition

As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph h

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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