Securities (Narrative) (Details)	6 Months Ended	12 Months Ended
Jun. 30, 2015 USD ($) security	Dec. 31, 2014 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Carrying value of pledged assets \| $	$ 29,845,000	$ 30,770,000
Equity method investments, other than temporary impairment \| $	$ 0	$ 0
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities in unrealized loss position	3
Obligations of U.S. Government Agencies and Corporations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment portfolio percentage	27.00%
Securities in unrealized loss position	15
Percentage of securities depreciated from their amortized cost basis	0.90%
Securities in unrealized loss positions for 12 months or more	8
Obligations of State and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment portfolio percentage	24.00%
Maturity term	5 years
Securities in unrealized loss position	26
Percentage of securities depreciated from their amortized cost basis	0.40%
Securities in unrealized loss positions for 12 months or more	1
Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment portfolio percentage	1.00%
Securities in unrealized loss position	9
Percentage of securities depreciated from their amortized cost basis	1.60%
Mortgage Loan [Member] \| Obligations of U.S. Government Agencies and Corporations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment portfolio percentage	48.00%

Investment Portfolio Percentage

No definition available.

Name:	juvf_InvestmentPortfolioPercentage
Namespace Prefix:	juvf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of securities depreciated from their amortized cost basis

+ References

No definition available.

+ Details

Name:	juvf_PercentageOfSecuritiesDepreciatedFromTheirAmortizedCostBasis
Namespace Prefix:	juvf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Securities In Unrealized Loss Positions For Twelve Months Or More

+ References

No definition available.

+ Details

Name:	juvf_SecuritiesInUnrealizedLossPositionsForTwelveMonthsOrMore
Namespace Prefix:	juvf_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The fair value of available-for-sale securities that serve as collateral for borrowings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5086-111524

+ Details

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

- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

+ Details

Name:	us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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

- Definition

This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the equity method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value subject to the equity accounting method. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 35

-Paragraph 32

-URI http://asc.fasb.org/extlink&oid=49116238&loc=d3e32787-111569

+ Details

Name:	us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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