Merger (Narrative) (Details) - USD ($)		3 Months Ended	12 Months Ended
	Apr. 30, 2018	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Apr. 29, 2018
Business Acquisition [Line Items]
Fair value gain				$ 415,000
Change in goodwill resulting from the merger		$ 92,000
Acquiree's common shares outstanding			5,099,729	5,092,048
Goodwill			$ 9,047,000	$ 9,139,000
Income/gain from unconsolidated subsidiary				$ 296,000
Federal statutory tax rate			21.00%	21.00%
Liverpool Community Bank [Member]
Business Acquisition [Line Items]
Acquisition date	Apr. 30, 2018
Business acquisition, name of acquired entity			Liverpool Community Bank
Total assets of acquiree	$ 45,360,000
Loans receivables of acquiree	32,091,000
Equity of acquiree	$ 9,246,000
Percentage of equity interest in acquiree, before acquisition					39.16%
Percentage of equity interest acquired	60.84%
Number of acquiree's common shares owned					1,214
Equity owned before acquisition	$ 4,622,000
Juniata's basis in Liverpool	5,037,000
Fair value gain	$ 415,000
Per share price of Liverpool shares	$ 4,050.00
Acquiree's common shares outstanding					3,100
Number of Juniata's share for each Liverpool share	202.6286
Number of shares issued upon the closing of acquisition	315,284
Fair value of shares issued for acquisition	$ 6,463,000
Closing stock price	$ 20.50
Approximate cash transaction of business acquisition	$ 1,362,000
Juniata's Step One adjusted basis in Liverpool	12,862,000
Step Two purchase price consideration	7,825,000
Goodwill	3,691,000	$ 3,599,000	$ 3,599,000	$ 3,691,000
Core deposit intangible assets acquired	$ 289,000
Intangible assets amortization period	10 years
Gross amortized cost basis	$ 32,091,000
Income/gain from unconsolidated subsidiary				296,000
Merger related costs				884,000
Merger related tax expense (benefit)				$ 123,000
Federal statutory tax rate				21.00%
Minimum [Member] | Liverpool Community Bank [Member]
Business Acquisition [Line Items]
Percentage of outstanding common stock to be purchased for cash	15.00%
Maximum [Member] | Liverpool Community Bank [Member]
Business Acquisition [Line Items]
Percentage of outstanding common stock to be purchased for cash	20.00%
Originally Reported [Member] | Liverpool Community Bank [Member]
Business Acquisition [Line Items]
Equity of acquiree	$ 9,246,000
Equity owned before acquisition	4,622,000
Juniata's basis in Liverpool	5,037,000
Fair value gain	415,000
Fair value of shares issued for acquisition	6,463,000
Approximate cash transaction of business acquisition	1,362,000
Juniata's Step One adjusted basis in Liverpool	12,862,000
Step Two purchase price consideration	7,825,000
Goodwill	$ 3,691,000
Adjustment [Member]
Business Acquisition [Line Items]
Tax benefit from removal of deferred tax liability				$ 406,000