v3.20.2

Note 12 - Subsequent Events (Details Textual) - Subsequent Event [Member]	Oct. 01, 2020
La Jolla [Member]
Promotion Agreement, Termination Notice (Day)	30 days
Promotion Agreement, Period Before Termination is Available (Year)	1 year
La Jolla [Member]
Promotion Agreement, Term (Year)	2 years
Promotion Agreement, Termination Notice (Day)	30 days

X

- Definition

The period before the promotion agreement can be terminated with notice.

+ References

No definition available.

+ Details

Name:	acrx_PromotionAgreementPeriodBeforeTerminationIsAvailable
Namespace Prefix:	acrx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The term of the promotion agreement.

+ References

No definition available.

+ Details

Name:	acrx_PromotionAgreementTerm
Namespace Prefix:	acrx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The period of notice of termination under the promotion agreement.

+ References

No definition available.

+ Details

Name:	acrx_PromotionAgreementTerminationNotice
Namespace Prefix:	acrx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

Name:	srt_CounterpartyNameAxis=acrx_LaJollaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: