Represents the number of shares in a unit.

No definition available.

Name:	bft_NumberOfSharesIssuedPerUnit
Namespace Prefix:	bft_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of warrants in a unit.

+ References

No definition available.

+ Details

Name:	bft_NumberOfWarrantsIssuedPerUnit
Namespace Prefix:	bft_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of new units issued during the period.

+ References

No definition available.

+ Details

Name:	bft_UnitsIssuedDuringPeriodSharesNewIssues
Namespace Prefix:	bft_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of securities into which each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares.

+ References

No definition available.

+ Details

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

- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

Name:	us-gaap_SharePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
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

No definition available.

+ Details

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

- Details

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

- Details

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

INITIAL PUBLIC OFFERING (Details) - $ / shares			9 Months Ended
INITIAL PUBLIC OFFERING (Details) - $ / shares	Aug. 26, 2020	Aug. 21, 2020	Sep. 30, 2020
Subsidiary, Sale of Stock [Line Items]
Number of shares issuable per warrant		1
Exercise price of warrants		$ 11.50
Initial Public Offering
Subsidiary, Sale of Stock [Line Items]
Number of units issued	146,703,345	130,000,000
Price per share		$ 10.00
Number of shares in a unit		1
Number of warrants in a unit			0.33
Number of shares issuable per warrant		1
Exercise price of warrants		$ 11.50
Over-allotment
Subsidiary, Sale of Stock [Line Items]
Number of units issued	16,703,345