XML 62 R42.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Stockholders' Equity - Additional Information (Detail) - USD ($) | 1 Months Ended | 12 Months Ended
--- | --- | ---
Nov. 30, 2018 | Jun. 30, 2018 | Jun. 30, 2017 | Aug. 31, 2016 | Jun. 30, 2016 | Apr. 30, 2016 | Jan. 31, 2016 | Jun. 30, 2015 | Dec. 31, 2012 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2010
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds from sale of common stock | $ 298,500,000 |  |  | $ 215,900,000 |  |  | $ 281,600,000 |  |  | $ 306,647,000 | $ 31,188,000 | $ 518,896,000 |
Share of common stock issued | 18,602,941 |  |  | 6,969,696 |  |  | 10,344,827 |  | 19,000,000 |  |  |  |
Common stock, par value |  |  |  |  |  |  |  |  |  | $ 0.0001 | $ 0.0001 |  |
Value of shares purchased by Baker Entities in public offerings |  |  |  |  |  |  |  |  |  | $ 14,000 | $ 12,000 |  |
Proceed from sale of stock and warrants |  |  |  |  |  |  |  |  | $ 80,500,000 |  |  |  |
Common stock sale price per share |  |  |  |  |  |  |  |  | $ 4.43 |  |  |  |
Options vesting period |  |  |  |  |  |  |  |  |  | 4 years |  |  |
Closing market price of Common stock |  |  |  |  |  |  |  |  |  | $ 16.17 |  |  |
Aggregate intrinsic value of stock options exercised |  |  |  |  |  |  |  |  |  | $ 11,200,000 | $ 24,400,000 | $ 43,200,000 |
Cash received from options exercised |  |  |  |  |  |  |  |  |  | $ 4,400,000 |  |  |
Weighted average per share fair value of options granted |  |  |  |  |  |  |  |  |  | $ 12.14 | $ 21.11 | $ 17.65 |
Unrecognized compensation costs |  |  |  |  |  |  |  |  |  | $ 153,700,000 |  |  |
Weighted average period cost expected to be recognized |  |  |  |  |  |  |  |  |  | 3 years 21 days |  |  |
Issuance of common stock pursuant to employee stock purchase plan |  |  |  |  |  |  |  |  |  | $ 3,682,000 | $ 4,522,000 | $ 3,131,000 |
Payment received from stockholder pursuant to a settlement agreement related to short-swing profits |  |  |  |  |  | $ 14,300,000 |  |  |  |  |  | $ 14,320,000 |
Prior stockholders percentage of equity holding |  |  |  |  |  | 10.00% |  |  |  |  |  |  |
Stock Options | Equity Incentive Plan 2010 |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Exercise price of Options as percentage of fair market value |  |  |  |  |  |  |  |  |  |  |  |  | 100.00%
Options maximum expiration term |  |  |  |  |  |  |  |  |  |  |  |  | 10 years
Options vesting period |  |  |  |  |  |  |  |  |  |  |  |  | 4 years
Number of common stock authorized for issuance |  |  |  |  |  |  |  |  |  | 26,919,256 |  |  |
Common stock available for grants |  |  |  |  |  |  |  |  |  | 6,676,769 |  |  |
Common stock reserved for issuance under stock purchase plan |  | 6,700,000 | 5,500,000 |  | 3,000,000 |  |  | 5,000,000 |  |  |  |  |
Stock Options | Equity Incentive Plan 2004 |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Exercise price of Options as percentage of fair market value |  |  |  |  |  |  |  |  |  | 100.00% |  |  |
Options vesting period |  |  |  |  |  |  |  |  |  | 4 years |  |  |
Number of periods additional number of shares could be added to shares authorized for issuance |  |  |  |  |  |  |  |  |  | 10 years |  |  |
Restricted Stock Units |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Unrecognized compensation costs |  |  |  |  |  |  |  |  |  | $ 7,500,000 |  |  |
Weighted average period cost expected to be recognized |  |  |  |  |  |  |  |  |  | 3 years 9 months 18 days |  |  |
Employee Stock Purchase Plan |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Number of common stock authorized for issuance |  |  |  |  |  |  |  |  |  | 1,925,000 |  |  |
Common stock reserved for issuance under stock purchase plan |  |  |  |  | 400,000 |  |  |  |  |  |  |  |
Term of ESPP Evergreen Provision |  |  |  |  |  |  |  |  |  | 10 years |  |  |
Common stock remained available for issuance pursuant to the Purchase Plan |  |  |  |  |  |  |  |  |  | 154,291 |  |  |
Eligible employees percentage of earnings withheld to purchase shares under purchase plan |  |  |  |  |  |  |  |  |  | 15.00% |  |  |
Purchase price of common stock as percentage of market value |  |  |  |  |  |  |  |  |  | 85.00% |  |  |
Issuance of common stock pursuant to employee stock purchase plan |  |  |  |  |  |  |  |  |  | 233,720 | 192,402 | 136,283 |
Average per share price of stock issued under purchase plan |  |  |  |  |  |  |  |  |  | $ 15.75 | $ 23.50 | $ 22.97 |
Weighted average per share fair value of purchase rights granted |  |  |  |  |  |  |  |  |  | $ 8.25 | $ 11.44 | $ 12.34 |
Issuance of common stock pursuant to employee stock purchase plan |  |  |  |  |  |  |  |  |  | $ 3,700,000 | $ 4,500,000 | $ 3,100,000 |
Expire on December 17, 2019 |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Warrants issued |  |  |  |  |  |  |  |  | 500,000 |  |  |  |
Warrants issuance price per share |  |  |  |  |  |  |  |  | $ 4.42 |  |  |  |
Warrant exercise price |  |  |  |  |  |  |  |  | $ 0.01 |  |  |  |
Warrant expiration date |  |  |  |  |  |  |  |  |  |  | Dec. 17, 2019 |  |
Issuance of warrant value |  |  |  |  |  |  |  |  | $ 2,200,000 |  |  |  |
Warrant risk free interest rate |  |  |  |  |  |  |  |  | 1.10% |  |  |  |
volatility percentage |  |  |  |  |  |  |  |  | 105.80% |  |  |  |
Warrant term |  |  |  |  |  |  |  |  | 7 years |  |  |  |
Warrants outstanding |  |  |  |  |  |  |  |  |  |  | 500,000 |  |
Description of warrant |  |  |  |  |  |  |  |  |  | Per their terms, the warrants to purchase 500,000 shares of common stock, of which 493,145 remained outstanding at December 31, 2018, may not be exercised if the holder’s ownership of the Company’s common stock would exceed 19.99 percent following such exercise. |  |  |
Dividend yield |  |  |  |  |  |  |  |  | 0.00% |  |  |  |
Registration Rights Agreement |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock, par value |  |  |  |  |  |  | $ 0.0001 |  |  |  |  |  |
Expiration period |  |  |  |  |  |  | 10 years |  |  |  |  |  |
Maximum amount of expense agreed to bear under the agreement |  |  |  |  |  |  | $ 50,000 |  |  |  |  |  |
Registration Rights Agreement | Baker Brothers Life Sciences L.P. |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Value of shares purchased by Baker Entities in public offerings |  |  |  | $ 43,000,000 |  |  | $ 75,000,000 |  |  |  |  |  |
Option To Purchase Additional Shares |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Share of common stock issued | 2,426,470 |  |  | 909,090 |  |  |  |  |  |  |  |  |

X
- Definition Aggregate number of shares of common stock issuable upon exercise of warrants. + References No definition available. + Details
Name: | acad_ClassOfWarrantOrRightIssued
Namespace Prefix: | acad_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Closing Market Price Of Common Stock + References No definition available. + Details
Name: | acad_ClosingMarketPriceOfCommonStock
Namespace Prefix: | acad_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Description of Warrant + References No definition available. + Details
Name: | acad_DescriptionOfWarrant
Namespace Prefix: | acad_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Eligible Employees Percentage of Earnings Withheld to Purchase Shares Under Purchase Plan + References No definition available. + Details
Name: | acad_EligibleEmployeesPercentageOfEarningsWithheldToPurchaseSharesUnderPurchasePlan
Namespace Prefix: | acad_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount per share or per unit assigned to the consideration received of equity securities issued for development stage entities. + References No definition available. + Details
Name: | acad_EquityIssuancePerShareAmount1
Namespace Prefix: | acad_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Exercise Price Of Options Percentage Of Fair Market Value Of Common Stock + References No definition available. + Details
Name: | acad_ExercisePriceOfOptionsPercentageOfFairMarketValueOfCommonStock
Namespace Prefix: | acad_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Expiration period of agreements. + References No definition available. + Details
Name: | acad_ExpirationPeriodOfAgreements
Namespace Prefix: | acad_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Issuance Of Warrants Price Per Share + References No definition available. + Details
Name: | acad_IssuanceOfWarrantsPricePerShare
Namespace Prefix: | acad_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Issuance Of Warrants, Value + References No definition available. + Details
Name: | acad_IssuanceOfWarrantsValue
Namespace Prefix: | acad_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Maximum expense agreed to bear under the agreement. + References No definition available. + Details
Name: | acad_MaximumExpenseAgreedToBearUnderTheAgreement
Namespace Prefix: | acad_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- References No definition available. + Details
Name: | acad_NotFoundDuringMigrationDeprecatedConceptFairValueAssumptionsExpectedTerm
Namespace Prefix: | acad_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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

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

X
- Definition Prior stockholders percentage of equity holding. + References No definition available. + Details
Name: | acad_PriorStockholdersPercentageOfEquityHolding
Namespace Prefix: | acad_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Proceeds From Issuance Of Common Stock And Warrants + References No definition available. + Details
Name: | acad_ProceedsFromIssuanceOfCommonStockAndWarrants
Namespace Prefix: | acad_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Remaining Shares Available For Issuance + References No definition available. + Details
Name: | acad_RemainingSharesAvailableForIssuance
Namespace Prefix: | acad_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Stock Issued, Employee Stock Purchase Plan, Average Price Per Share + References No definition available. + Details
Name: | acad_StockIssuedEmployeeStockPurchasePlanAveragePricePerShare
Namespace Prefix: | acad_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Term Of Evergreen Provision Employee Stock Purchase Plan + References No definition available. + Details
Name: | acad_TermOfEvergreenProvisionEmployeeStockPurchasePlan
Namespace Prefix: | acad_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Warrants Expiration Date + References No definition available. + Details
Name: | acad_WarrantsExpirationDate
Namespace Prefix: | acad_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ClassOfStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(4)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of warrants or rights outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_ClassOfWarrantOrRightOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Face amount or stated value per share of common stock. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -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_CommonStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -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_CommonStockValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Unrecognized cost of unvested share-based compensation awards. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash inflow associated with the amount received by a corporation from a shareholder during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromContributedCapital
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash inflow from the additional capital contribution to the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109197908&loc=SL79508275-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromStockOptionsExercised
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of additional shares authorized for issuance under an established share-based compensation plan. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Purchase price of common stock expressed as a percentage of its fair value. + References No definition available. + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares issued during the period as a result of an employee stock purchase plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -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_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of new stock issued during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -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 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate change in value for stock issued during the period as a result of employee stock purchase plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -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 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=acad_EquityIncentivePlanTwentyTenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=acad_EquityIncentivePlanTwoThousandFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=acad_EmployeeStockPurchasePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ClassOfWarrantOrRightAxis=acad_ExpireOnDecemberSeventeenTwoThousandAndNineteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=acad_RegistrationRightsAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_MajorityShareholderMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=acad_OptionToPurchaseAdditionalSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |