Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation (Summary Of Unvested Shares) (Details)

v2.4.1.9
Stock-Based Compensation (Summary Of Unvested Shares) (Details) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]    
Number of options, Cancelled   (85,000)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod
Weighted average fair value at grant date, Vested $ 0.69rnn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue $ 0.28rnn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue
Nonvested Options [Member]    
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]    
Number of nonvested options, outstanding 3,233,499rnn_NumberOfNonvestedOptionsOutstanding
/ us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis
= rnn_NonvestedOptionsMember
1,400,000rnn_NumberOfNonvestedOptionsOutstanding
/ us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis
= rnn_NonvestedOptionsMember
Number of options, Granted 2,528,499us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis
= rnn_NonvestedOptionsMember
 
Number of options, Vested (695,000)rnn_ShareBasedCompensationArragementByShareBasedPaymentAwardOptionsVestedInPeriodGross
/ us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis
= rnn_NonvestedOptionsMember
 
Number of options, Cancelled     
Number of nonvested options, outstanding 3,233,499rnn_NumberOfNonvestedOptionsOutstanding
/ us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis
= rnn_NonvestedOptionsMember
1,400,000rnn_NumberOfNonvestedOptionsOutstanding
/ us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis
= rnn_NonvestedOptionsMember
Weighted average fair value at grant date, Unvested $ 0.34rnn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis
= rnn_NonvestedOptionsMember
 
Weighted average fair value at grant date, Granted $ 0.69rnn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantedWeightedAverageGrantDateFairValue
/ us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis
= rnn_NonvestedOptionsMember
 
Weighted average fair value at grant date, Vested $ 0.41rnn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue
/ us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis
= rnn_NonvestedOptionsMember
 
Weighted average fair value at grant date, Cancelled     
Weighted average fair value at grant date, Unvested $ 0.60rnn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis
= rnn_NonvestedOptionsMember
$ 0.34rnn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis
= rnn_NonvestedOptionsMember