Lease generated in real estate income.

No definition available.

Name:	ffntf_LeaseGeneratedInRealEstateIncome
Namespace Prefix:	ffntf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Lease receivables Interest during the period.

+ References

No definition available.

+ Details

Name:	ffntf_LeaseReceivablesInterestDuringPeriod
Namespace Prefix:	ffntf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Leases.

+ References

No definition available.

+ Details

Name:	ffntf_LeasesLineItems
Namespace Prefix:	ffntf_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Lessee incremental borrowing rate percentage.

+ References

No definition available.

+ Details

Name:	ffntf_LesseeIncrementalBorrowingRatePercentage
Namespace Prefix:	ffntf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Indicates (true false) whether lessor has option to extend operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=121576215&loc=SL77919359-209981

+ Details

Name:	us-gaap_LessorOperatingLeaseExistenceOfOptionToExtend
Namespace Prefix:	us-gaap_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of operating lease expense. Excludes sublease income.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918638-209977

+ Details

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

- Definition

The net cost of operation of other real estate (including provisions for real estate losses, rental income, and gains and losses on sales of real estate).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.14(d))
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

+ Details

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

- Definition

Present value of lease payments not yet received by lessor and amount expected to be derived from underlying asset, following end of lease term guaranteed by lessee or other third party unrelated to lessor, from sales-type and direct financing leases.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121576215&loc=SL77919391-209981

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121576215&loc=SL77919379-209981

+ Details

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

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Leases - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended	18 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Jun. 30, 2021	Dec. 31, 2019
Leases [Line Items]
Lessor, operating lease options to renew			true
Operating lease expense	$ 2,400	$ 821	$ 4,868	$ 2,375
Lease receivable	10,696		10,696		$ 11,045	$ 10,696	$ 33,500
Lease interest in real estate income			1,361		$ 11,019
Real estate income	$ 2,669	$ 2,734	5,559	$ 5,631
Lease generated in real estate income			$ 4,198
Minimum
Leases [Line Items]
Lessee incremental borrowing rate percentage						10.25%
Maximum
Leases [Line Items]
Lessee incremental borrowing rate percentage						17.00%