SHAREHOLDERS EQUITY - Stock based compensation - Financial Performance Units (Details) - USD ($) $ in Millions		3 Months Ended
May 01, 2019	Mar. 31, 2020
Financial Performance Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		1,866
Financial Performance Units Granted Prior to 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period (in years)		2 years
Percent of awards accruing at maximum threshold		50.00%
Remainder threshold awards		50.00%
Maximum number of shares can be issued		10,000
Unrecognized compensation expense		$ 0.1
Unrecognized compensation expense recognition period (in years)		1 year 9 months 18 days
Financial Performance Units Granted Prior to 2019 \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Financial performance threshold percentage		150.00%
Financial Performance Units Granted Prior to 2019 \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Financial performance threshold percentage		0.00%
Financial Performance Units Granted in 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period (in years)	2 years
Granted (in shares)	62,569	1,866
Maximum percentage of shares can be issued		100.00%
Maximum number of shares can be issued		58,000
Unrecognized compensation expense		$ 0.7
Unrecognized compensation expense recognition period (in years)		3 years 9 months 18 days
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	5 years
Financial Performance Units Granted in 2019 \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Financial performance threshold percentage	150.00%
Financial Performance Units Granted in 2019 \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Financial performance threshold percentage	0.00%

The percentage of threshold stated for achieving entity's financial performance metrics.

No definition available.

Name:	myfw_FinancialPerformanceMetricsThresholdPercentage
Namespace Prefix:	myfw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percent Of Awards Accruing At Maximum Threshold

+ References

No definition available.

+ Details

Name:	myfw_PercentOfAwardsAccruingAtMaximumThreshold
Namespace Prefix:	myfw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of threshold for remaining awards.

+ References

No definition available.

+ Details

Name:	myfw_RemainderThresholdAwardsPercentage
Namespace Prefix:	myfw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

+ Details

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

- Definition

Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

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

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

- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

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

- Definition

Maximum number of shares that may be issued in accordance with the plan as a proportion of outstanding capital stock.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOutstandingStockMaximum
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=myfw_FinancialPerformanceUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=myfw_FinancialPerformanceUnitsGrantedPriorTo2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	us-gaap_AwardTypeAxis=myfw_FinancialPerformanceUnitsGrantedIn2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: