No definition available.

Name:	bmtx_AmountPaid
Namespace Prefix:	bmtx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow associated with the amount received from entity's raising of capital via private rather than public placement.

+ References

No definition available.

+ Details

Name:	bmtx_ProceedsFromIssuanceOfPrivatePlacements
Namespace Prefix:	bmtx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	bmtx_RelatedPartyTransactionsDetailsLineItems
Namespace Prefix:	bmtx_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Total payment of administrative and support service.

+ References

No definition available.

+ Details

Name:	bmtx_TotalPaymentOfAdministrativeAndSupportService
Namespace Prefix:	bmtx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

With respect to a business combination completed during the period, this element provides a description of the business, other than the name, which may include the industry, size, products and other important information.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

+ Details

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

- Definition

A description of each transaction that is recognized separately from the acquisition of assets and assumptions of liabilities in the business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsDescription
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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=123467817&loc=d3e21475-112644

+ Details

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

- 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

- Definition

Face amount or stated value per share of common stock.

+ 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(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Amount paid to managing member or general partner, affiliate of managing member or general partner, or affiliate of limited liability company (LLC) or limited partnership (LP) for administrative services provided to the LLC or LP, for example, but not limited to, salaries, rent, or overhead costs.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3367-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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

- 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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

+ Details

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

- Definition

The cash inflow associated with the amount received from entity's raising of capital via private rather than public placement.

+ 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 http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585

+ Details

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

- Definition

The cash inflow from a borrowing supported by a written promise to pay an obligation.

+ 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 (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585

+ Details

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

- Definition

Description of stock transaction which may include details of the offering (IPO, private placement), a description of the stock sold, percentage of subsidiary's or equity investee's stock sold, a description of the investors and whether the stock was issued in a business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4582445-111684

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=123454820&loc=SL4569655-111683

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684

+ Details

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

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766

Reference 2: 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(19)(a))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(1))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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

- Definition

Number of shares of stock issued attributable to transactions classified as other.

+ References

No definition available.

+ Details

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

- Definition

Number of shares (or other type of equity) forfeited during the period.

+ References

No definition available.

+ Details

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

- Definition

Value of shares of stock issued attributable to transactions classified as other.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=bmtx_FounderSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=bmtx_SponsorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=bmtx_ChardanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_TitleOfIndividualAxis=srt_PresidentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=bmtx_BusinessCombinationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=bmtx_SponsorAndChardanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Related Party Transactions (Details) - USD ($)		1 Months Ended			12 Months Ended
Related Party Transactions (Details) - USD ($)	Nov. 13, 2017	Sep. 21, 2018	Dec. 31, 2017	Nov. 27, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transactions (Details) [Line Items]
Common stock, par value (in Dollars per share)	$ 0.0001
Sponsor forfeited (in Shares)					80,278
Aggregate amount					$ 20,002,872
Offering cost				$ 300,000
Amount drawn on notes			$ 2,000
Additional borrowings							$ 105,500
Payment of affiliate an aggregate of per month					2,000
Total support services costs incurred					20,000	$ 24,000
Total amount of expense					$ 165,384	$ 200,000
Founder Shares [Member]
Related Party Transactions (Details) [Line Items]
Purchase of common stock shares (in Shares)	4,312,500
Common stock aggregate price	$ 25,000
Sponsor forfeited (in Shares)	562,500	80,278
Business combination, description	The Initial Stockholders have agreed, subject to limited exceptions, not to transfer, assign or sell any of their Founder Shares until the earlier to occur of: (A) one year after the completion of a Business Combination or (B) subsequent to a Business Combination, (x) if the last sale price of the Class A common stock equals or exceeds $12.00 per share (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations and the like) for any 20 trading days within any 30-trading day period commencing at least 150 days after a Business Combination, or (y) the date on which the Company completes a liquidation, merger, capital stock exchange or other similar transaction that results in all of the Company’s stockholders having the right to exchange their shares of common stock for cash, securities or other property.
Sponsor [Member]
Related Party Transactions (Details) [Line Items]
Purchase of aggregate shares (in Shares)					5,810,000
Chardan [Member]
Related Party Transactions (Details) [Line Items]
Purchase of aggregate shares (in Shares)					750,000
President [Member] \| Business Combination [Member]
Related Party Transactions (Details) [Line Items]
Business combination, description					The Company agreed to pay an entity affiliated with the President a fee of approximately $16,667 per month until the earlier of the consummation of the Business Combination or liquidation. A bonus of $78,000 was paid out after the successful completion of the Initial Public Offering.
Private Placement Warrants [Member]
Related Party Transactions (Details) [Line Items]
Aggregate price (in Dollars per share)					$ 1.00
Purchase of aggregate shares (in Shares)					385,778
Aggregate amount					$ 385,778
Private Placement Warrants [Member] \| Sponsor and Chardan [Member]
Related Party Transactions (Details) [Line Items]
Aggregate amount					$ 6,560,000
Aggregate price (in Dollars per share)					$ 1.00
Purchase of aggregate shares (in Shares)					6,560,000
Private placement warrants, description					Each whole Private Placement Warrant is exercisable for one whole share of Class A Common Stock at a price of $11.50 per share (subject to adjustment for stock splits, stock dividends, reorganizations, recapitalizations and the like and for certain issuances of equity or equity-linked securities).