Loans - Additional Information (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($) category component class contract	Mar. 31, 2016 contract	Mar. 31, 2017 USD ($) category component class contract	Dec. 31, 2016 USD ($)	Jun. 01, 2013 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired financing receivable, unpaid principal balance	$ 15,655,000		$ 15,655,000	$ 16,071,000
Financing receivable individually evaluated for impairment minimum amount	100,000
Individually evaluated for impairment	$ 100,000
Payment delays limit (in days)	90 days
Impaired financing receivable commitment to lend	$ 26,000		$ 26,000
Reasonable period to classify from troubled debt restructuring non performing loans to performing loans (in months)	6 months
Number of contracts | contract			0
Recorded investment	$ 8,998,000		$ 8,998,000	9,180,000
Real estate acquired through foreclosure	547,000		547,000	839,000
Mortgage loans in process of foreclosure, amount	$ 78,000		$ 78,000	167,000
Number of categories considered not criticized and rated as, Pass | category	6		6
Minimum period after which loans are considered as substandard (in days)	90 days
The total number of components that represents the allowance for loan losses | component	2		2
The number of classes that groups of loans are collectively evaluated for impairment | class	2		2
Period considered for quarter moving average which used in calculating historical charge off (in months)	36 months
Commercial Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of contracts | contract	1
Recorded investment	$ 103,000
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of contracts | contract	1	5
Recorded investment	$ 239,000
Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of contracts | contract	3
Recorded investment	$ 173,000
Luzerne National Bank Corporation
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair value					$ 878,000
Purchased loans | Luzerne National Bank Corporation
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired financing receivable, unpaid principal balance					1,211,000
Contractually required payments					1,783,000
Cash flows expected to be collected					941,000
Certain loans acquired in transfer not accounted for as debt securities non accretable yield					842,000
Accretable yield					$ 63,000
Real estate mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of categories in which real estate loans segmented | category	3
Real estate mortgage | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired financing receivable, unpaid principal balance	$ 12,230,000		$ 12,230,000	12,353,000
Real estate mortgage | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired financing receivable, unpaid principal balance	$ 3,237,000		$ 3,237,000	$ 3,477,000