v3.8.0.1

Note 16 - 401(k) Plan (Details Textual) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Defined Contribution Plan, Employer Discretionary Contribution Percentage | 4.00% |  |
Contributions by Employer to Postemployment Benefit Obligations | $ 0.3 | $ 0.3 | $ 0.3

X
- References No definition available. + Details
Name: | acrx_ContributionsByEmployerToPostemploymentBenefitObligations
Namespace Prefix: | acrx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | acrx_DefinedContributionPlanEmployerDiscretionaryContributionPercentage
Namespace Prefix: | acrx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration