XML 85 R73.htm IDEA: XBRL DOCUMENT v3.20.4

Other Real Estate Owned and Repossessions - Summary of Repossessed Assets Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Other Real Estate And Other Assets Acquired In Foreclosure [Line Items]
Sales proceeds	$ (413)	$ (664)
Gross gains	48	39
Gross losses	(47)	(77)
Net gains (losses)	1	(38)
Impairment	(10)	(38)
Repossessed Assets [Member]
Other Real Estate And Other Assets Acquired In Foreclosure [Line Items]
Beginning balance	256	229
Transfers from loans	1,095	1,027
Sales proceeds	(674)	(569)
Gross gains		2
Gross losses	(432)	(433)
Net gains (losses)	(432)	(431)
Ending balance	$ 245	$ 256

X

- Definition

Other real estate and other assets acquired in foreclosure.

+ References

No definition available.

+ Details

Name:	fusb_OtherRealEstateAndOtherAssetsAcquiredInForeclosureLineItems
Namespace Prefix:	fusb_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Other real estate gross gains.

+ References

No definition available.

+ Details

Name:	fusb_OtherRealEstateGrossGains
Namespace Prefix:	fusb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Other real estate gross losses.

+ References

No definition available.

+ Details

Name:	fusb_OtherRealEstateGrossLosses
Namespace Prefix:	fusb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Other real estate net income loss.

+ References

No definition available.

+ Details

Name:	fusb_OtherRealEstateNetIncomeLoss
Namespace Prefix:	fusb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Real estate owned, transfer to loan.

+ References

No definition available.

+ Details

Name:	fusb_RealEstateOwnedTransferToLoan
Namespace Prefix:	fusb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The charge against earnings in the period to reduce the carrying amount of real property to fair value.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2921-110230

+ Details

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

X

- Definition

Carrying amount as of the balance sheet date of assets other than real property that were received in full or partial satisfaction of a debt arrangement through foreclosure proceedings or defeasance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5162-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4437-111522

+ Details

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

X

- Definition

The cash inflow associated with the sale of other real estate not otherwise defined in the taxonomy.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3179-108585

+ Details

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

X

- Details

Name:	srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=fusb_RepossessedAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: