(Loss) earnings per share (Table) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Earnings per Share [Abstract]
Net (loss) income attributable to Seanergy Maritime Holdings Corp.	$ (193,768)	$ (197,756)	$ 132
Weighted Average Number Of Shares Outstanding Basic And Diluted	11,576,576	7,314,636	5,861,129
Net (loss) income per common share - basic and diluted	$ (16.74)	$ (27.04)	$ 0.02

The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

No definition available.

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