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Data Type:	xbrli:sharesItemType
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Represent each unit of share which is made of.

No definition available.

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Data Type:	xbrli:sharesItemType
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Period Type:	duration

Number of units issued during period shares.

No definition available.

Name:	alf_NumberOfUnitsIssuedDuringPeriodShares
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Data Type:	xbrli:sharesItemType
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Represent the redemption of warrants condition share price.

No definition available.

Name:	alf_RedemptionOfWarrantsConditionSharePrice
Namespace Prefix:	alf_
Data Type:	dtr:perShareItemType
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Period Type:	duration

Represent the redemption period.

No definition available.

Name:	alf_RedemptionPeriod
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Period Type:	duration

Redemption price per warrant.

No definition available.

Name:	alf_RedemptionPricePerWarrant
Namespace Prefix:	alf_
Data Type:	dtr:perShareItemType
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Period Type:	duration

When determining the condition for transfer of shares without restriction after a business combination, the number of days in which the share price must exceed the specified amount.

No definition available.

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Namespace Prefix:	alf_
Data Type:	xbrli:durationItemType
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Warrant exercisable term after initial business combination.

No definition available.

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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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-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

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

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.

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

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Balance Type:	na
Period Type:	instant

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

No definition available.

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

Period between issuance and expiration of outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Name:	us-gaap_WarrantsAndRightsOutstandingTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

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

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_ClassOfWarrantOrRightAxis=alf_PublicWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

Name:	us-gaap_ClassOfWarrantOrRightAxis=us-gaap_WarrantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: