Quarterly report pursuant to Section 13 or 15(d)

Warrants (Schedule Of Fair Value Of Warrants Issued) (Details)

v2.4.1.9
Warrants (Schedule Of Fair Value Of Warrants Issued) (Details) (USD $)
Mar. 31, 2015
Dec. 31, 2014
Class of Warrant or Right [Line Items]    
Fair value $ 3,652,936rnn_InvestmentWarrantsFairValue $ 3,768,351rnn_InvestmentWarrantsFairValue
March 31, 2011 Warrants To Institutional Investors [Member]    
Class of Warrant or Right [Line Items]    
Fair value 217,200rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateEWarrantsToInstitutionalInvestorsMember 		319,277rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateEWarrantsToInstitutionalInvestorsMember
December 4, 2012 Warrants To Institutional Investors [Member]    
Class of Warrant or Right [Line Items]    
Fair value 92,949rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateFWarrantsToInstitutionalInvestorsMember 		90,052rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateFWarrantsToInstitutionalInvestorsMember
December 4, 2012 Warrants To Placement Agent [Member]    
Class of Warrant or Right [Line Items]    
Fair value 14,452rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateFWarrantsToPlacementAgentMember 		14,595rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateFWarrantsToPlacementAgentMember
July 26, 2013 Warrants To Institutional Investors [Member]    
Class of Warrant or Right [Line Items]    
Fair value 813,100rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateGWarrantsToInstitutionalInvestorsMember 		788,314rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateGWarrantsToInstitutionalInvestorsMember
July 26, 2013 Warrants To Placement Agent [Member]    
Class of Warrant or Right [Line Items]    
Fair value 26,249rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateGWarrantsToPlacementAgentMember 		30,594rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateGWarrantsToPlacementAgentMember
October 16, 2013 Warrants To Institutional Investors [Member]    
Class of Warrant or Right [Line Items]    
Fair value 967,516rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateHWarrantsToInstitutionalInvestorsMember 		949,756rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateHWarrantsToInstitutionalInvestorsMember
October 16, 2013 Warrants To Placement Agent [Member]    
Class of Warrant or Right [Line Items]    
Fair value 81,384rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateHWarrantsToPlacementAgentMember 		96,563rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateHWarrantsToPlacementAgentMember
January 21, 2014 Warrants To Institutional Investors [Member]    
Class of Warrant or Right [Line Items]    
Fair value $ 1,440,086rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateIWarrantsToInstitutionalInvestorsMember 		$ 1,479,200rnn_InvestmentWarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= rnn_DateIWarrantsToInstitutionalInvestorsMember