Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies (Details Textaul)

Summary of Significant Accounting Policies (Details Textaul) (USD $)
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Marketable Securities, Current $ 3,247,509us-gaap_MarketableSecuritiesCurrent   $ 0us-gaap_MarketableSecuritiesCurrent
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs 749,386us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options 838,163us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Remaining Contractual Term 4 years    
Payments Of Deferred Offering Costs $ 30,321cobu_PaymentsOfDeferredOfferingCosts $ 14,982cobu_PaymentsOfDeferredOfferingCosts