XML 121 R101.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Note 21 - Fair Value of Financial Instruments - Summary of Assets and Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Level 3) (Details) - Fair Value, Inputs, Level 3 [Member] $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2016 USD ($)
Other Assets [Member] |
Fair value | $ 280
Minimum [Member] | Other Assets [Member] |
Quantitative range of unobservable inputs | 9.00%
Weighted Average [Member] | Other Assets [Member] |
Quantitative range of unobservable inputs | 9.50%
Maximum [Member] | Other Assets [Member] |
Quantitative range of unobservable inputs | 10.00%
Impaired Loans [Member] |
Fair value | $ 1,568
Impaired Loans [Member] | Minimum [Member] |
Quantitative range of unobservable inputs | 9.00%
Impaired Loans [Member] | Weighted Average [Member] |
Quantitative range of unobservable inputs | 9.50%
Impaired Loans [Member] | Maximum [Member] |
Quantitative range of unobservable inputs | 10.00%
OREO [Member] |
Fair value | $ 4,858
OREO [Member] | Minimum [Member] |
Quantitative range of unobservable inputs | 9.00%
OREO [Member] | Weighted Average [Member] |
Quantitative range of unobservable inputs | 9.50%
OREO [Member] | Maximum [Member] |
Quantitative range of unobservable inputs | 10.00%

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Percentage of adjustment to the observed price for a similar asset or liability when an identical transaction does not exist, used as an input to measure fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueInputsComparabilityAdjustments
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=fusb_ImpairedLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=fusb_OreoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |