Operating Lease Obligations - ROU Assets and Lease Liabilities (Details)	12 Months Ended
	Dec. 31, 2019 USD ($) item	Dec. 31, 2018 USD ($)	Jan. 01, 2019 USD ($)
Leases [Abstract]
Number of Operating Lease Obligations | item	4
Consolidated statements of condition classification of the Company's ROU assets and lease liabilities
Practical expedients package	true
Practical expedients, use of hindsight	true
Operating lease ROU assets	$ 464,000		$ 556,000
Operating lease ROU assets, statement of financial position	juvf:AccruedInterestReceivableAndOtherAssets
Lease liability	$ 469,000		$ 556,000
Operating lease liabilities, statement of financial position	juvf:AccruedInterestPayableAndOtherLiabilities
Options to renew	true
Weighted-average remaining operating lease term	6 years 9 months 18 days
Weighted-average discount rate	4.95%
Total operating cost	$ 120,000	$ 109,000
Total operating lease payment to related parties	$ 23,000	$ 23,000