Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Detail)

v2.4.1.9
Subsequent Events - Additional Information (Detail) (USD $)
9 Months Ended 0 Months Ended
Feb. 28, 2015
Feb. 28, 2014
Feb. 06, 2015
Sep. 26, 2014
Apr. 09, 2015
Mar. 06, 2015
Apr. 01, 2015
May 31, 2014
Apr. 30, 2010
Mar. 02, 2015
Subsequent Event [Line Items]                    
Common stock, shares authorized 100,000,000us-gaap_CommonStockSharesAuthorized             100,000,000us-gaap_CommonStockSharesAuthorized 100,000,000us-gaap_CommonStockSharesAuthorized  
Convertible notes $ 3,247,741us-gaap_ConvertibleDebt   $ 1,500,000us-gaap_ConvertibleDebt $ 2,000,000us-gaap_ConvertibleDebt            
Convertible note conversion price per share $ 0.75us-gaap_DebtInstrumentConvertibleConversionPrice1                  
Cash interest payment 170,934us-gaap_InterestPaid 165,354us-gaap_InterestPaid                
Warrants to purchase shares of common stock, exercise price $ 0.50us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1                  
Face amount of notes 0cydy_ConvertibleNotesFaceAmount             1,200,000cydy_ConvertibleNotesFaceAmount    
Alpha Venture Capital Partners, L.P.                    
Subsequent Event [Line Items]                    
Convertible note conversion price per share $ 1.00us-gaap_DebtInstrumentConvertibleConversionPrice1
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= cydy_AlphaVentureCapitalPartnersLPMember
  $ 1.00us-gaap_DebtInstrumentConvertibleConversionPrice1
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= cydy_AlphaVentureCapitalPartnersLPMember
$ 1.00us-gaap_DebtInstrumentConvertibleConversionPrice1
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= cydy_AlphaVentureCapitalPartnersLPMember
           
Warrants to purchase shares of common stock 325,000us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= cydy_AlphaVentureCapitalPartnersLPMember
                 
Warrants to purchase shares of common stock, exercise price $ 0.50us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= cydy_AlphaVentureCapitalPartnersLPMember
  $ 0.50us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= cydy_AlphaVentureCapitalPartnersLPMember
$ 0.50us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= cydy_AlphaVentureCapitalPartnersLPMember
           
Face amount of notes 3,500,000cydy_ConvertibleNotesFaceAmount
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= cydy_AlphaVentureCapitalPartnersLPMember
  1,500,000cydy_ConvertibleNotesFaceAmount
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= cydy_AlphaVentureCapitalPartnersLPMember
2,000,000cydy_ConvertibleNotesFaceAmount
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= cydy_AlphaVentureCapitalPartnersLPMember
           
Convertible note maturity date Sep. 26, 2016   May 05, 2015 Sep. 26, 2016            
2012 Equity Incentive Plan                    
Subsequent Event [Line Items]                    
Warrants to purchase shares of common stock 325,000us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_PlanNameAxis
= cydy_TwoThousandTwelveStockIncentivePlanMember
                 
Subsequent Event                    
Subsequent Event [Line Items]                    
Common stock, shares authorized                   200,000,000us-gaap_CommonStockSharesAuthorized
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
Convertible notes term         3 years          
Convertible notes         3,046,250us-gaap_ConvertibleDebt
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
         
Accrued but unpaid interest         96,595us-gaap_InterestPayableCurrentAndNoncurrent
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
         
Convertible note conversion price per share         $ 0.75us-gaap_DebtInstrumentConvertibleConversionPrice1
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
         
Common stock issued upon conversion of notes         4,181,079us-gaap_DebtConversionConvertedInstrumentSharesIssued1
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
         
Cash interest payment         7,028us-gaap_InterestPaid
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
         
Warrants to purchase shares of common stock         5,555,000us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
150,000us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
       
Warrants to purchase shares of common stock, exercise price         $ 1.00us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
$ 0.83us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
       
Exercisable warrants, expire period           5 years        
Exercisable warrants, vesting percentage           50.00%us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
       
Exercisable warrants, expire period           2 years        
Subsequent Event | Alpha Venture Capital Partners, L.P.                    
Subsequent Event [Line Items]                    
Face amount of notes             $ 1,500,000cydy_ConvertibleNotesFaceAmount
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= cydy_AlphaVentureCapitalPartnersLPMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
     
Convertible note maturity date             May 05, 2015      
Subsequent Event | Alpha Venture Capital Partners, L.P. | Revised                    
Subsequent Event [Line Items]                    
Convertible note maturity date             Aug. 05, 2015      
Subsequent Event | Exercisable through December 2015                    
Subsequent Event [Line Items]                    
Warrants to purchase shares of common stock         186,667us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_ClassOfWarrantOrRightAxis
= cydy_ExercisablePeriodOneMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
         
Subsequent Event | Exercisable until January 15, 2016                    
Subsequent Event [Line Items]                    
Warrants to purchase shares of common stock         160,000us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
/ us-gaap_ClassOfWarrantOrRightAxis
= cydy_ExercisablePeriodTwoMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
         
Subsequent Event | 2012 Equity Incentive Plan | Stock Options                    
Subsequent Event [Line Items]                    
Shares available for future issuance                   2,000,000cydy_IncreaseInSharesOfCommonStockAuthorizedForIssuance
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
/ us-gaap_PlanNameAxis
= cydy_TwoThousandTwelveStockIncentivePlanMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember