XML 43 R36.htm IDEA: XBRL DOCUMENT v3.24.2.u1

Stockholders' Equity - Additional Information (Details) - USD ($)			1 Months Ended			3 Months Ended		6 Months Ended
	Jul. 01, 2024	Feb. 28, 2023	Aug. 05, 2024	Mar. 31, 2023	Mar. 31, 2021	Jun. 30, 2024	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Subsidiary Sale Of Stock [Line Items]
Offering costs								$ 116,000
Proceeds from issuance of common stock upon exercise of common stock warrants								$ 29,543,000	$ 15,590,000
Warrants outstanding						2,281,115		2,281,115
Public Offerings
Subsidiary Sale Of Stock [Line Items]
Proceeds from issuance of common stock, net of commissions and offering expenses				$ 296,800,000
Shares issued and sold				19,461,538
Offering price per share				$ 16.25			$ 16.25
Underwriting discounts and commissions				$ 19,000,000
Offering costs				$ 500,000
Public Offerings | Common Stock
Subsidiary Sale Of Stock [Line Items]
Shares issued and sold							19,461,538
Public Offering
Subsidiary Sale Of Stock [Line Items]
Warrants to purchase common stock exercised								9,192,289	2,927,570
Proceeds from issuance of common stock upon exercise of common stock warrants								$ 48,900,000	$ 15,600,000
Warrants outstanding						987,500		987,500
Public Offering | Subsequent Events
Subsidiary Sale Of Stock [Line Items]
Proceeds from issuance of common stock upon exercise of common stock warrants	$ 5,300,000		$ 19,400,000
Warrant exercised date	Jul. 01, 2024
2021 ATM Facility
Subsidiary Sale Of Stock [Line Items]
Selling commission per shares sold percentage					3.00%
Maximum value of common stock to be issued under agreement					$ 75,000,000
2023 ATM Facility
Subsidiary Sale Of Stock [Line Items]
Proceeds from issuance of common stock, net of commissions and offering expenses								$ 21,000,000
Sales under the agreement						$ 0
Maximum value of common stock to be issued under agreement		$ 150,000,000
Shares issued and sold								1,396,888
Common stock remaining for future sales								$ 104,400,000
2021 ATM Facility and 2023 ATM Facility
Subsidiary Sale Of Stock [Line Items]
Proceeds from issuance of common stock, net of commissions and offering expenses									$ 37,100,000
Shares issued and sold									2,168,539

X

- Definition

Common shares aggregate offering price authorized remaining capacity available.

+ References

No definition available.

+ Details

Name:	etnb_CommonSharesAggregateOfferingPriceAuthorizedRemainingCapacityAvailable
Namespace Prefix:	etnb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Common shares offering price authorized.

+ References

No definition available.

+ Details

Name:	etnb_CommonSharesOfferingPriceAuthorized
Namespace Prefix:	etnb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Number of warrants exercised during the period.

+ References

No definition available.

+ Details

Name:	etnb_NumberOfWarrantsExercisedDuringThePeriod
Namespace Prefix:	etnb_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Selling commission per shares sold percentage.

+ References

No definition available.

+ Details

Name:	etnb_SellingCommissionPerSharesSoldPercentage
Namespace Prefix:	etnb_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Underwriting discounts and commissions.

+ References

No definition available.

+ Details

Name:	etnb_UnderwritingDiscountsAndCommissions
Namespace Prefix:	etnb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Date the warrants or rights are exercisable, in YYYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-3

+ Details

Name:	us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of warrants or rights outstanding.

+ References

No definition available.

+ Details

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

X

- Definition

The cash outflow for cost incurred directly with the issuance of an equity security.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-15

+ Details

Name:	us-gaap_PaymentsOfStockIssuanceCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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
-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

X

- Definition

The cash inflow associated with the amount received from holders exercising their stock warrants.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-14

+ Details

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

X

- Definition

Amount of consideration received by subsidiary or equity investee in exchange for shares of stock issued or sold. Includes amount of cash received, fair value of noncash assets received, and fair value of liabilities assumed by the investor.

+ References

No definition available.

+ Details

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

X

- 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

X

- Definition

Number of new stock issued during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481004/946-505-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(4)(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 5: 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(28))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1

Reference 7: 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_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
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_SubsidiarySaleOfStockLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

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

X

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=etnb_FollowOnOfferingMember
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:

X

- Details

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

X

- Details

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

X

- Details

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