Contract with Customer, Refund Liability, Amortization of Deferred Gain

No definition available.

Name:	akba_ContractWithCustomerRefundLiabilityAmortizationOfDeferredGain
Namespace Prefix:	akba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Contract with Customer, Refund Liability, Amortization of Discount

+ References

No definition available.

+ Details

Name:	akba_ContractWithCustomerRefundLiabilityAmortizationOfDiscount
Namespace Prefix:	akba_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Contract with Customer, Refund Liability, Gross

+ References

No definition available.

+ Details

Name:	akba_ContractWithCustomerRefundLiabilityGross
Namespace Prefix:	akba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contract with Customer, Refund Liability, Interest Rate

+ References

No definition available.

+ Details

Name:	akba_ContractWithCustomerRefundLiabilityInterestRate
Namespace Prefix:	akba_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual Arrangement, Royalties Agreement, Interest Rate, Effective Percentage

+ References

No definition available.

+ Details

Name:	akba_ContractualArrangementRoyaltiesAgreementInterestRateEffectivePercentage
Namespace Prefix:	akba_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual Arrangement, Royalties Agreement, Liability, Noncurrent

+ References

No definition available.

+ Details

Name:	akba_ContractualArrangementRoyaltiesAgreementLiabilityNoncurrent
Namespace Prefix:	akba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual Arrangement, Royalties Agreement, Maximum Aggregate Royalty Payout Capacity

+ References

No definition available.

+ Details

Name:	akba_ContractualArrangementRoyaltiesAgreementMaximumAggregateRoyaltyPayoutCapacity
Namespace Prefix:	akba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual Arrangement, Royalties Agreement, Maximum Annual Royalty Payout Capacity

+ References

No definition available.

+ Details

Name:	akba_ContractualArrangementRoyaltiesAgreementMaximumAnnualRoyaltyPayoutCapacity
Namespace Prefix:	akba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual Arrangement, Royalties Agreement, Percentage

+ References

No definition available.

+ Details

Name:	akba_ContractualArrangementRoyaltiesAgreementPercentage
Namespace Prefix:	akba_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Revenue, Remaining Performance Obligation, Variable Consideration, Profit Share Percentage

+ References

No definition available.

+ Details

Name:	akba_RevenueRemainingPerformanceObligationVariableConsiderationProfitSharePercentage
Namespace Prefix:	akba_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Royalty Payment

+ References

No definition available.

+ Details

Name:	akba_RoyaltyPayment
Namespace Prefix:	akba_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Royalty True-Up Payments

+ References

No definition available.

+ Details

Name:	akba_RoyaltyTrueUpPayments
Namespace Prefix:	akba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Tiered Royalty Payments as a Percentage of Net Sales

+ References

No definition available.

+ Details

Name:	akba_TieredRoyaltyPaymentsAsAPercentageOfNetSales
Namespace Prefix:	akba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Tiered Royalty Payments, Percentage

+ References

No definition available.

+ Details

Name:	akba_TieredRoyaltyPaymentsPercentage
Namespace Prefix:	akba_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 808
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479402/808-10-50-1

+ Details

Name:	us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_CommonStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-11

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479837/606-10-45-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-8

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479837/606-10-45-2

+ Details

Name:	us-gaap_ContractWithCustomerLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as noncurrent.

+ References

+ Details

Name:	us-gaap_ContractWithCustomerLiabilityNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of interest income (expense) classified as nonoperating.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4A

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 48
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-48

+ Details

Name:	us-gaap_InterestIncomeExpenseNonoperatingNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of cash paid for royalties during the current period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 25
-Subparagraph (g)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-25

+ Details

Name:	us-gaap_PaymentsForRoyalties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow from the additional capital contribution to the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (a)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-14

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (a)
-SubTopic 10
-Topic 606
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-13

+ Details

Name:	us-gaap_RevenueRemainingPerformanceObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Cash received on stock transaction after deduction of issuance costs.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockConsiderationReceivedOnTransaction
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_PrivatePlacementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=akba_ViforInternationalLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=akba_LicenseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=us-gaap_LicenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=akba_CSLViforMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=akba_ViforInternationalLimitedFirstInvestmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=akba_ViforInternationalLimitedSecondInvestmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=akba_HealthCareRoyaltyPartnersIVL.P.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

LIABILITY RELATED TO SETTLEMENT ROYALTIES, WORKING CAPITAL FUND LIABILITY AND LIABILITY RELATED TO SALE OF FUTURE ROYALTIES - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			3 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	May 31, 2017	Mar. 31, 2026	Mar. 31, 2025	May 31, 2028	May 31, 2027	May 31, 2026	Dec. 31, 2025	Jul. 01, 2025	Jul. 10, 2024	May 03, 2024	Mar. 18, 2022	Feb. 18, 2022	Feb. 25, 2021
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock, issued (in shares)				267,898,415					265,424,818
Annual effective interest rate (as percent)				0.00%
Interest expense				$ (4,691)	$ (7,770)
Refund liability to customer, amortization of discount				1,200	1,100
Refund liability to customer, amortization of deferred gain				800	1,000
Maximum annual royalty payout capacity		$ 13,000
Percentage of royalty payment to be received once maximum annual royalty payout has been paid		85.00%
Maximum aggregate royalty payout capacity		$ 150,000
Liability related to sale of future royalties, net of current portion				$ 50,414					$ 50,608						$ 44,800
Private Placement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sale of stock, price per share (in dollars per share)	$ 5.00
Number of shares sold in offering (in shares)	4,000,000
Aggregate net proceeds from offering	$ 20,000
Vifor (International) Ltd.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Annual effective interest rate (as percent)				21.20%
Interest expense				$ 3,600	5,400
Refund liability to customer, gross													$ 40,000
Vifor (International) Ltd. \| License Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock, issued (in shares)			3,571,429
Sale of stock, price per share (in dollars per share)			$ 14.00
Proceeds from common stock sold			$ 50,000
Vifor (International) Ltd. \| License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue, remaining performance obligation, profit share percentage														66.00%
Deferred revenue														$ 25,000
Long-term deferred revenue	$ 13,600		$ 4,700
Transaction price														$ 43,300
Refund liability to customer, interest rate (as percent)													15.00%
Vifor (International) Ltd. \| License \| Private Placement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Long-term deferred revenue				18,300
CSL Vifor
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Tiered royalty payments as a percentage of net sales											$ 450,000
Refund liability to customer, interest rate (as percent)												15.00%
Royalty payments										$ 40,000
CSL Vifor \| Forecast
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty true-up payments						$ 40,000	$ 20,000	$ 10,000
CSL Vifor \| Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Tiered royalty payments as a percentage of net sales											$ 450,000
Tiered royalty payments, percentage												14.00%
CSL Vifor \| Minimum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Tiered royalty payments, percentage												8.00%
Vifor International Limited, First Investment \| License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Long-term deferred revenue				4,700
Vifor International Limited, Second Investment \| License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Long-term deferred revenue				13,600
HealthCare Royalty Partners IV, L.P.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payments for royalties				$ 500	$ 500