The line of credit facility fee for credit agreement amendment based on a loans outstanding, expressed as a percentage.

No definition available.

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Balance Type:	na
Period Type:	duration

- Definition

The line of credit facility exit fee, expressed as a percentage.

+ References

No definition available.

+ Details

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Namespace Prefix:	btai_
Data Type:	dtr-types:percentItemType
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Period Type:	duration

- Definition

Maximum amount the Lenders agree to permit the entity to invest in subsidiary.

+ References

No definition available.

+ Details

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Namespace Prefix:	btai_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of the fee that accompanies borrowing money under the debt instrument.

+ 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 210.5-02.22(b))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI https://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3367-108585

+ Details

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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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3255-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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Period Type:	duration

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

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Subsequent Events (Details) - USD ($) $ in Thousands			1 Months Ended		9 Months Ended
Subsequent Events (Details) - USD ($) $ in Thousands	Nov. 13, 2023	Nov. 02, 2023	Nov. 14, 2023	May 31, 2021	Sep. 30, 2023
Subsequent Events
Proceeds from issuance of common stock					$ 24,657
Credit Facility
Subsequent Events
Maximum investment allowed					25,000
Jefferies Sale Agreement
Subsequent Events
Proceeds from issuance of common stock					$ 23,918
Jefferies Sale Agreement \| Maximum
Subsequent Events
Proceeds from issuance of common stock				$ 100,000
Subsequent Event
Subsequent Events
Payments for restructuring			$ 3,748
Subsequent Event \| Credit Facility
Subsequent Events
Maximum investment allowed	$ 30,000
Debt instrument fee	$ 180
Amendment fee (as a percent)	0.25%
Exit fee (as a percent)	0.25%
Subsequent Event \| Jefferies Sale Agreement \| Maximum
Subsequent Events
Proceeds from issuance of common stock		$ 150,000