v3.19.2

Note 8 - Liability Related to Sale of Future Royalties (Details Textual) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended	3 Months Ended		6 Months Ended		39 Months Ended
	Sep. 18, 2015	Sep. 30, 2015	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Proceeds From Sale of Royalty and Milestone Rights	$ 65.0	$ 65.0
Royalty Arrangment Maximum Payments	$ 195.0	$ 195.0
Effective Annual Interest Rate			4.20%	13.40%	1.40%	13.50%	13.00%
Prospective Average Rate for Remaining Term of the Agreement			4.20%
Estimate Future Payments Receivable Over Remaining Life of Arrangment					$ 36.0
Contingent Gain (Loss) on Royalty Monetization Arrangement					$ 29.0
Effective Interest Over Life of Liability Related to Sale of Future Royalties					0.00%
Net Income (Loss) from Change Estimate on Liability Related to Sale of Future Royalties			$ (2.7)		$ (2.7)
Net Income (Loss) Per Share, Change Estimate on Liability Related to Sale of Future Royalties			$ (0.03)		$ (0.03)
PDL [Member]
Percentage of Royalties and Rights Under Agreement	75.00%
PDL [Member] | First Four Commercial Milestones [Member]
Percentage of Royalties and Rights Under Agreement	80.00%
Commercial Milestones Value Maximum Amount Available	$ 35.6
AcelRX [Member] | First Four Commercial Milestones [Member]
Commercial Milestones Value Maximum Amount Available	$ 44.5

X

- Definition

The maximum value of commercial milestone payments available to the company.

+ References

No definition available.

+ Details

Name:	acrx_CommercialMilestonesValueMaximumAmountAvailable
Namespace Prefix:	acrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The amount of contingent gain (loss) on royalty monetization arrangement.

+ References

No definition available.

+ Details

Name:	acrx_ContingentGainLossOnRoyaltyMonetizationArrangement
Namespace Prefix:	acrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Effective annual rate for a liability related to sale of future royalties.

+ References

No definition available.

+ Details

Name:	acrx_EffectiveAnnualInterestRate
Namespace Prefix:	acrx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The percentage of effective interest over the life of the liability related to sale of future royalties.

+ References

No definition available.

+ Details

Name:	acrx_EffectiveInterestOverLifeOfLiabilityRelatedToSaleOfFutureRoyalties
Namespace Prefix:	acrx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of estimate future payments receivable from a counter party over the remaining life of arrangment.

+ References

No definition available.

+ Details

Name:	acrx_EstimateFuturePaymentsReceivableOverRemainingLifeOfArrangment
Namespace Prefix:	acrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The amount of net income (loss) from change estimate on liability related to sale of future royalties.

+ References

No definition available.

+ Details

Name:	acrx_NetIncomeLossFromChangeEstimateOnLiabilityRelatedToSaleOfFutureRoyalties
Namespace Prefix:	acrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The amount of net income (loss) per share for change estimate on liability related to sale of future royalties.

+ References

No definition available.

+ Details

Name:	acrx_NetIncomeLossPerShareChangeEstimateOnLiabilityRelatedToSaleOfFutureRoyalties
Namespace Prefix:	acrx_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Percentage of royalties or milestone rights to be received under the agreement.

+ References

No definition available.

+ Details

Name:	acrx_PercentageOfRoyaltiesAndRightsUnderAgreement
Namespace Prefix:	acrx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of proceeds from the sale of royalty and milestone rights.

+ References

No definition available.

+ Details

Name:	acrx_ProceedsFromSaleOfRoyaltyAndMilestoneRights
Namespace Prefix:	acrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Represents prospective average rate for remaining term of the agreement.

+ References

No definition available.

+ Details

Name:	acrx_ProspectiveAverageRateForRemainingTermOfTheAgreement
Namespace Prefix:	acrx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The capped amount of payments of company required to make to PDL.

+ References

No definition available.

+ Details

Name:	acrx_RoyaltyArrangmentMaximumPayments
Namespace Prefix:	acrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	dei_LegalEntityAxis=acrx_PDLMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_TypeOfArrangementAxis=acrx_FirstFourCommercialMilestonesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=acrx_AcelRXMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: