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Share-based Compensation (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 17, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares outstanding under Equity plan	1,068,515us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	843,442us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	144,019us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Stock options award, expiration	10 years
Weighted Average exercise Price of Options Outstanding	$ 2.89us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	$ 3.76us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	$ 18.28us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Total intrinsic value of options exercised	$ 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	$ 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense related to unvested options	633,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember
Maturity period of weighted average period of compensation expenses	2 years 2 months 12 days
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maturity period of weighted average period of compensation expenses	2 years 4 months 24 days
Unrecognized compensation cost related to unvested stock awards	$ 629,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockUnitsRSUMember
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options award, vesting period	3 years
Percentage holding for stock options exercise price	10.00%abio_PercentageHoldingForStockOptionsExercisePrice / us-gaap_RangeAxis = us-gaap_MinimumMember
Minimum | Incentive Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of exercise price of stock option	100.00%us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent / us-gaap_AwardTypeAxis = abio_IncentiveStockOptionMember / us-gaap_RangeAxis = us-gaap_MinimumMember
Minimum | Incentive Stock Option | Stockholders
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of exercise price of stock option	110.00%us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent / us-gaap_AwardTypeAxis = abio_IncentiveStockOptionMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = us-gaap_PrincipalOwnerMember
Minimum | Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Units award, requisite service period	3 years
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options award, vesting period	4 years
Maximum | Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Units award, requisite service period	4 years
2013 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future				2,250,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized / us-gaap_PlanNameAxis = abio_TwoThousandAndThirteenPlanMember
Number of shares outstanding under Equity plan	1,437,477us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber / us-gaap_PlanNameAxis = abio_TwoThousandAndThirteenPlanMember
Shares reserved for future	672,852us-gaap_CommonStockCapitalSharesReservedForFutureIssuance / us-gaap_PlanNameAxis = abio_TwoThousandAndThirteenPlanMember
Options and awards granted	420,279us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod / us-gaap_PlanNameAxis = abio_TwoThousandAndThirteenPlanMember	1,160,535us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod / us-gaap_PlanNameAxis = abio_TwoThousandAndThirteenPlanMember
Two Thousand And Four Stock Option Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares outstanding under Equity plan	59,776us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber / us-gaap_PlanNameAxis = abio_TwoThousandAndFourStockOptionPlanMember
Weighted Average exercise Price of Options Outstanding	$ 15.10us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice / us-gaap_PlanNameAxis = abio_TwoThousandAndFourStockOptionPlanMember
Other Stock Option Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares outstanding under Equity plan	42,291us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber / us-gaap_PlanNameAxis = abio_OtherStockOptionPlanMember
Weighted Average exercise Price of Options Outstanding	$ 17.78us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice / us-gaap_PlanNameAxis = abio_OtherStockOptionPlanMember

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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.

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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.

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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.

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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.

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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).

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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.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Purchase price of common stock expressed as a percentage of its fair value.

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Number of share instruments newly issued under a share-based compensation plan.

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