XML 99 R82.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Subsequent Events - Additional Information (Detail) - USD ($) $ in Millions | 2 Months Ended | 4 Months Ended |  |
--- | --- | --- | --- | ---
Mar. 01, 2018 | Dec. 31, 2017 | Sep. 14, 2017 | Dec. 31, 2016
Subsequent Event [Line Items] |  |  |  |
Common stock, shares issued |  | 11,956,752 |  | 21,230
LPC [Member] |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Common stock, shares issued |  | 873,778 | 123,516 |
Gross proceeds |  | $ 2.0 |  |
Common stock available for sale under offering |  | $ 9.0 |  |
Subsequent Event [Member] | LPC [Member] |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Common stock, shares issued | 800,000 |  |  |
Gross proceeds | $ 1.3 |  |  |
Common stock available for sale under offering | $ 7.6 |  |  |

X
- Definition Common stock sales agreement net amount. + References No definition available. + Details
Name: | achv_CommonStockSalesAgreementNetAmount
Namespace Prefix: | achv_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Proceeds from issuance of common stock gross. + References No definition available. + Details
Name: | achv_ProceedsFromIssuanceOfCommonStockGross
Namespace Prefix: | achv_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References No definition available. + Details
Name: | us-gaap_SubsequentEventLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_CounterpartyNameAxis=achv_LincolnParkCapitalFundLimitedLiabilityCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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