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