Name:	akca_AllocableArrangementConsideration
Namespace Prefix:	akca_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Non-cash sublicense fee expenses recognized in the period they are incurred under the development, commercialization and license agreement with Ionis Pharmaceuticals, Inc. related to the lipid drugs licensed under the agreement.

No definition available.

Name:	akca_NonCashSublicenseFeeExpenses
Namespace Prefix:	akca_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The percentage of license fees, milestone payments and royalties paid as a sublicense fee to Ionis Pharmaceuticals, Inc. under the development, commercialization and license agreement and services agreement .

No definition available.

Name:	akca_PercentageOfLicenseFeesMilestonePaymentsAndRoyaltiesPaidAsSublicenseFee
Namespace Prefix:	akca_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The period of time after inception of the collaboration agreement for an initial public offering (IPO) to be completed, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	akca_PeriodFromInceptionOfAgreementForIPOToBeCompleted
Namespace Prefix:	akca_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The amount of the upfront payment received during the period under the collaboration agreement that was paid as a sublicense fee to Ionis Pharmaceuticals, Inc.

No definition available.

Name:	akca_PortionOfUpfrontPaymentPaidAsSublicenseFee
Namespace Prefix:	akca_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The premium received if an initial public offering (IPO) is not completed within 15 months after inception of the collaboration agreement.

No definition available.

Name:	akca_PremiumReceivedIfIPOIsNotCompletedAfterInceptionOfAgreement
Namespace Prefix:	akca_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The total amount of the premium received over the trading price of common stock at the time of purchase.

No definition available.

Name:	akca_PremiumReceivedOnSharesIssued
Namespace Prefix:	akca_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Sublicense fee expenses recognized in the period they are incurred under the development, commercialization and license agreement with Ionis Pharmaceuticals, Inc. related to the lipid drugs licensed under the agreement.

No definition available.

Name:	akca_SublicenseFeeExpenses
Namespace Prefix:	akca_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amount of upfront payments received during the period under the collaboration agreement.

No definition available.

Name:	akca_UpfrontPaymentReceived
Namespace Prefix:	akca_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.