v3.8.0.1

Note 1 - Organization and Summary of Significant Accounting Policies (Details Textual) $ in Thousands |  | 1 Months Ended | 12 Months Ended | 27 Months Ended
--- | --- | --- | --- | ---
Sep. 18, 2015 USD ($) | Sep. 30, 2015 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($) | Dec. 31, 2017 USD ($)
Inventory Write-down |  |  | $ 369 |  |  |
Proceeds From Sale of Royalty and Milestone Rights | $ 65,000 | $ 65,000 |  |  |  |
Royalty Arrangment Maximum Payments | $ 195,000 | 195,000 |  |  |  |
Net Proceeds from Sale of Future Royalties |  | $ 61,200 |  |  | 61,184 | $ 61,184
Effective Annual Interest Rate | 14.00% | 14.00% |  |  |  |
Interest Income [Member] |  |  |  |  |  |
Asset Impairment Charges |  |  | $ 0 |  | $ 500 |
Minimum [Member] |  |  |  |  |  |
Property, Plant and Equipment, Useful Life |  |  | 3 years |  |  |
Maximum [Member] |  |  |  |  |  |
Property, Plant and Equipment, Useful Life |  |  | 5 years |  |  |
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] |  |  |  |  |  |
Number of Major Customers |  |  | 2 | 2 | 2 |
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Two Customers [Member] |  |  |  |  |  |
Concentration Risk, Percentage |  |  | 100.00% | 100.00% | 100.00% |
Accounts Receivable [Member] | Customer Concentration Risk [Member] | One Customer [Member] |  |  |  |  |  |
Concentration Risk, Percentage |  |  | 79.00% | 71.00% | 84.00% |

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 Net proceeds from sale of future royalties. + References No definition available. + Details
Name: | acrx_NetProceedsFromSaleOfFutureRoyalties
Namespace Prefix: | acrx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the number of major customers accounting for 10% or more of the specified concentration risk benchmark, which includes, but not limited to, sales revenue, accounts receivable, etc. + References No definition available. + Details
Name: | acrx_NumberOfMajorCustomers
Namespace Prefix: | acrx_
Data Type: | xbrli:integerItemType
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 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
- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 + Details
Name: | us-gaap_AssetImpairmentCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611 + Details
Name: | us-gaap_ConcentrationRiskPercentage1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 330 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=66092785&loc=d3e4542-108314 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 330 -SubTopic 10 -Section 35 -Paragraph 1C -URI http://asc.fasb.org/extlink&oid=68049868&loc=SL66093883-108312 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.2) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 330 -SubTopic 10 -Section 35 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=68049868&loc=SL66093879-108312 + Details
Name: | us-gaap_InventoryWriteDown
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_InterestIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=acrx_TwoCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_AccountsReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=acrx_OneCustomerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |