Basis of Presentation and Informational Disclosures (Details 2) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Stock-based aggregate disclosure
Stock-based employee compensation expense	$ 898,000	$ 1,200,000
Income Taxes- Uncertain Tax Positions
Unrecognized tax benefits liability	0us-gaap_UnrecognizedTaxBenefits
Accrued amount of payment of interest or penalties	0
Stock options
Stock-based aggregate disclosure
Compensation expense for unvested common share awards which is yet to be recognized	4,400,000
Restricted common shares
Stock-based aggregate disclosure
Compensation expense for unvested common share awards which is yet to be recognized	$ 13,500,000

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 50

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-Name Staff Accounting Bulletin (SAB)

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