v3.23.2

Note 13 - Commitments and Contingencies (Details Textual)	Jul. 06, 2021	Jun. 08, 2021
Purported Shareholder v. Company - Violation of Sections 10(b) and 20(a) of the Exchange Act and SEC Rule 10b-5 [Member]
Loss Contingency, Number of Defendants		2
Purported Shareholder v. Company - Alleged Misstatements as the Shareholder [Member]
Loss Contingency, Number of Defendants	10

X

- Definition

Number of defendants named in a legal action.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483076/450-20-50-4

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483076/450-20-50-9

+ Details

Name:	us-gaap_LossContingencyNumberOfDefendants
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	srt_LitigationCaseAxis=acrx_PurportedShareholderVCompanyViolationOfSections10bAnd20aOfTheExchangeActAndSecRule10b5Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_LitigationCaseAxis=acrx_PurportedShareholderVCompanyAllegedMisstatementsAsTheShareholderMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: