Consolidated Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Costs and Expenses:
General and administrative	$ 6,013us-gaap_GeneralAndAdministrativeExpense	$ 5,832us-gaap_GeneralAndAdministrativeExpense	$ 5,012us-gaap_GeneralAndAdministrativeExpense
Research and development	14,489us-gaap_ResearchAndDevelopmentExpense	6,507us-gaap_ResearchAndDevelopmentExpense	12,287us-gaap_ResearchAndDevelopmentExpense
Total Operating Costs and Expenses	20,502us-gaap_OperatingExpenses	12,339us-gaap_OperatingExpenses	17,299us-gaap_OperatingExpenses
Loss from Operations	(20,502)us-gaap_OperatingIncomeLoss	(12,339)us-gaap_OperatingIncomeLoss	(17,299)us-gaap_OperatingIncomeLoss
Other Income (Expense):
Change in fair value of warrant liability	620us-gaap_FairValueAdjustmentOfWarrants	0us-gaap_FairValueAdjustmentOfWarrants	0us-gaap_FairValueAdjustmentOfWarrants
Other income (expense)	95us-gaap_OtherNonoperatingIncomeExpense	(12)us-gaap_OtherNonoperatingIncomeExpense	(18)us-gaap_OtherNonoperatingIncomeExpense
Interest income	3us-gaap_InvestmentIncomeInterest	33us-gaap_InvestmentIncomeInterest	33us-gaap_InvestmentIncomeInterest
Total Other Income	718us-gaap_NonoperatingIncomeExpense	21us-gaap_NonoperatingIncomeExpense	15us-gaap_NonoperatingIncomeExpense
Loss from Continuing Operations	(19,784)	(12,318)	(17,284)
Income from Discontinued Operations	0	0	216
Net Loss	(19,784)us-gaap_ProfitLoss	(12,318)us-gaap_ProfitLoss	(17,068)us-gaap_ProfitLoss
Net Loss Attributable to Non-controlling Interest	0	(1)	0
Net Loss Attributable to Synthetic Biologics, Inc. and Subsidiaries	$ (19,784)us-gaap_NetIncomeLoss	$ (12,317)us-gaap_NetIncomeLoss	$ (17,068)us-gaap_NetIncomeLoss
Net Income (Loss) Per Share - Basic and Dilutive
Continuing operations (in dollars per share)	$ (0.32)	$ (0.27)	$ (0.50)
Discontinued operations (in dollars per share)	$ 0	$ 0	$ 0.01
Net Income (Loss) Per Share Attributable to Synthetic Biologics, Inc. and Subsidiaries (in dollars per share)	$ (0.32)us-gaap_EarningsPerShareBasicAndDiluted	$ (0.27)us-gaap_EarningsPerShareBasicAndDiluted	$ (0.49)us-gaap_EarningsPerShareBasicAndDiluted
Weighted average number of shares outstanding during the period - Basic and Dilutive (in shares)	61,945,356	45,667,813	34,896,592

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.