LOANS AND THE ALLOWANCE FOR LOAN LOSSES - Narrative (Details) $ in Thousands	12 Months Ended
Dec. 31, 2022 USD ($) loan	Dec. 31, 2021 USD ($) loan
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans held for investment	$ 2,476,135	$ 1,954,168
Loans, net	2,452,230	1,935,405
Recorded investments	3,100	4,300
Additional funds to loans classified as TDRs	$ 0	$ 0
Number of loans classified as TDRs \| loan	0	3
Modified loan maturity period	1 year
Interest only payment period for modified loans		6 months
Doubtful
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans held for investment	$ 0	$ 0
COVID-19
Financing Receivable, Allowance for Credit Loss [Line Items]
Delinquent over period	30 days
Payments period	2 years
Number of loans modified \| loan	49
Outstanding balance of modified loans	$ 78,400
Number of loans in deferral \| loan	14
Loans in deferral, amount	$ 3,300
Loans modified for temporary payment, period	180 days
Consumer and Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans held for investment	$ 49,954	34,758
Loans held for investment, unpaid principal balance	23,400
PPP Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans held for investment	7,100	46,800
PPP Loans \| Cash, Securities and Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans held for investment	$ 7,100	$ 46,800
Percent of loans on total loan segment	4.30%	17.90%
MSLP loan
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans held for investment	$ 6,600	$ 6,800
Percent of loans on total loan segment	1.80%	3.30%
MSLP loan \| COVID-19
Financing Receivable, Allowance for Credit Loss [Line Items]
Number of loans \| loan	5	5
Loans, net	$ 6,600	$ 6,800
Commercial and Industrial
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans held for investment	$ 361,028	$ 203,584
Number of loans, 90 days delinquent and accruing interest \| loan	1	1
Small Mortgage Loan
Financing Receivable, Allowance for Credit Loss [Line Items]
Recorded investments		$ 100
Commercial and Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Recorded investments		1,200
Commercial Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Recorded investments		700
Simmons Bank
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans held for investment	$ 234,700	$ 356,700

The amount of funds lent to borrower with a loan classified as TDRs.

No definition available.

Name:	myfw_FinancingReceivableAdditionalFundsToLoansClassifiedAsTdrs
Namespace Prefix:	myfw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of financing receivable modified not treated as troubled debt restructuring.

+ References

No definition available.

+ Details

Name:	myfw_FinancingReceivableLoanModificationNotTreatedAsTroubledDebtRestructuring
Namespace Prefix:	myfw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of financing receivable modified not treated as troubled debt restructuring and are still in deferral period.

+ References

No definition available.

+ Details

Name:	myfw_FinancingReceivableModificationLoansInDeferralAmount
Namespace Prefix:	myfw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of financing receivables that have been modified and not treated as troubled debt restructuring.

+ References

No definition available.

+ Details

Name:	myfw_FinancingReceivableModificationNumberOfContracts
Namespace Prefix:	myfw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of financing receivables that have been modified and not treated as troubled debt restructuring and are still in deferral period.

+ References

No definition available.

+ Details

Name:	myfw_FinancingReceivableModificationNumberOfContractsInDeferral
Namespace Prefix:	myfw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Interest only payment period for modified loans.

+ References

No definition available.

+ Details

Name:	myfw_InterestOnlyPaymentsPeriodForModifiedLoans
Namespace Prefix:	myfw_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The period of track record will be taken as base for modification of loans.

+ References

No definition available.

+ Details

Name:	myfw_LoanModificationPastCreditRiskAnalysisPeriodBase
Namespace Prefix:	myfw_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum payment delinquent period was taken as base for loan modification.

+ References

No definition available.

+ Details

Name:	myfw_LoanModificationThresholdPeriodPaymentDelinquent
Namespace Prefix:	myfw_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of loans held for investment under the fair value option.

+ References

No definition available.

+ Details

Name:	myfw_LoansHeldForInvestmentFairValueOption
Namespace Prefix:	myfw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Period of loans modified for temporary payment.

+ References

No definition available.

+ Details

Name:	myfw_LoansModifiedForTemporaryPaymentPeriod
Namespace Prefix:	myfw_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Modified Loan Maturity Period

+ References

No definition available.

+ Details

Name:	myfw_ModifiedLoanMaturityPeriod
Namespace Prefix:	myfw_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of loans.

+ References

No definition available.

+ Details

Name:	myfw_NumberOfLoans
Namespace Prefix:	myfw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of loans which are 90 days delinquent and accruing interest.

+ References

No definition available.

+ Details

Name:	myfw_NumberOfLoans90DaysDelinquentAndAccruingInterest
Namespace Prefix:	myfw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of loan classified as troubled debt restructuring.

+ References

No definition available.

+ Details

Name:	myfw_NumberOfLoansClassifiedAsTroubledDebtRestructuring
Namespace Prefix:	myfw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of class of loan on a particular portfolio segment.

+ References

No definition available.

+ Details

Name:	myfw_PercentOfLoansOnTotalLoanSegment
Namespace Prefix:	myfw_
Data Type:	dtr-types:percentItemType
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_FinancingReceivableAllowanceForCreditLossesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

+ Details

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

- Definition

Amount, before allowance and fees, of loans and leases receivable. Excludes loans and leases covered under loss sharing agreements.

+ References

+ Details

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

- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7)
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

+ Details

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

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_DoubtfulMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnusualOrInfrequentItemAxis=myfw_Covid19Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=myfw_ConsumerAndOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=myfw_PaycheckProtectionProgramLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=myfw_CashSecuritiesAndOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=myfw_MainStreetLendingProgramLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=myfw_CommercialAndIndustrialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=myfw_SmallMortgageLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=myfw_CommercialAndRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=myfw_CommercialLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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